diff --git a/src/Redux.Sandbox.Universal/App.xaml b/src/Redux.Sandbox.Universal/App.xaml
deleted file mode 100644
index 0e1d69f..0000000
--- a/src/Redux.Sandbox.Universal/App.xaml
+++ /dev/null
@@ -1,8 +0,0 @@
-<Application
-    x:Class="Redux.Sandbox.Universal.App"
-    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
-    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-    xmlns:local="using:Redux.Sandbox.Universal"
-    RequestedTheme="Light">
-
-</Application>
diff --git a/src/Redux.Sandbox.Universal/App.xaml.cs b/src/Redux.Sandbox.Universal/App.xaml.cs
deleted file mode 100644
index b827c8a..0000000
--- a/src/Redux.Sandbox.Universal/App.xaml.cs
+++ /dev/null
@@ -1,38 +0,0 @@
-using System;
-using Windows.ApplicationModel;
-using Windows.ApplicationModel.Activation;
-using Windows.UI.Xaml;
-using Windows.UI.Xaml.Controls;
-using Windows.UI.Xaml.Navigation;
-
-namespace Redux.Sandbox.Universal
-{
-    sealed partial class App : Application
-    {
-        public static IStore<int> CounterStore = new Store<int>(0,CounterReducer.Execute);
-
-        public App()
-        {
-            this.InitializeComponent();
-        }
-
-        protected override void OnLaunched(LaunchActivatedEventArgs e)
-        {
-            Frame rootFrame = Window.Current.Content as Frame;
-
-            if (rootFrame == null)
-            {
-                rootFrame = new Frame();
-
-                Window.Current.Content = rootFrame;
-            }
-
-            if (rootFrame.Content == null)
-            {
-                rootFrame.Navigate(typeof(MainPage), e.Arguments);
-            }
-
-            Window.Current.Activate();
-        }
-    }
-}
diff --git a/src/Redux.Sandbox.Universal/Assets/LockScreenLogo.scale-200.png b/src/Redux.Sandbox.Universal/Assets/LockScreenLogo.scale-200.png
deleted file mode 100644
index 735f57a..0000000
Binary files a/src/Redux.Sandbox.Universal/Assets/LockScreenLogo.scale-200.png and /dev/null differ
diff --git a/src/Redux.Sandbox.Universal/Assets/SplashScreen.scale-200.png b/src/Redux.Sandbox.Universal/Assets/SplashScreen.scale-200.png
deleted file mode 100644
index 023e7f1..0000000
Binary files a/src/Redux.Sandbox.Universal/Assets/SplashScreen.scale-200.png and /dev/null differ
diff --git a/src/Redux.Sandbox.Universal/Assets/Square150x150Logo.scale-200.png b/src/Redux.Sandbox.Universal/Assets/Square150x150Logo.scale-200.png
deleted file mode 100644
index af49fec..0000000
Binary files a/src/Redux.Sandbox.Universal/Assets/Square150x150Logo.scale-200.png and /dev/null differ
diff --git a/src/Redux.Sandbox.Universal/Assets/Square44x44Logo.scale-200.png b/src/Redux.Sandbox.Universal/Assets/Square44x44Logo.scale-200.png
deleted file mode 100644
index ce342a2..0000000
Binary files a/src/Redux.Sandbox.Universal/Assets/Square44x44Logo.scale-200.png and /dev/null differ
diff --git a/src/Redux.Sandbox.Universal/Assets/Square44x44Logo.targetsize-24_altform-unplated.png b/src/Redux.Sandbox.Universal/Assets/Square44x44Logo.targetsize-24_altform-unplated.png
deleted file mode 100644
index f6c02ce..0000000
Binary files a/src/Redux.Sandbox.Universal/Assets/Square44x44Logo.targetsize-24_altform-unplated.png and /dev/null differ
diff --git a/src/Redux.Sandbox.Universal/Assets/StoreLogo.png b/src/Redux.Sandbox.Universal/Assets/StoreLogo.png
deleted file mode 100644
index 7385b56..0000000
Binary files a/src/Redux.Sandbox.Universal/Assets/StoreLogo.png and /dev/null differ
diff --git a/src/Redux.Sandbox.Universal/Assets/Wide310x150Logo.scale-200.png b/src/Redux.Sandbox.Universal/Assets/Wide310x150Logo.scale-200.png
deleted file mode 100644
index 288995b..0000000
Binary files a/src/Redux.Sandbox.Universal/Assets/Wide310x150Logo.scale-200.png and /dev/null differ
diff --git a/src/Redux.Sandbox.Universal/CounterActions.cs b/src/Redux.Sandbox.Universal/CounterActions.cs
deleted file mode 100644
index ca0d980..0000000
--- a/src/Redux.Sandbox.Universal/CounterActions.cs
+++ /dev/null
@@ -1,6 +0,0 @@
-namespace Redux.Sandbox.Universal
-{
-    public class IncrementAction : IAction { }
-
-    public class DecrementAction : IAction { }
-}
diff --git a/src/Redux.Sandbox.Universal/CounterReducer.cs b/src/Redux.Sandbox.Universal/CounterReducer.cs
deleted file mode 100644
index 554297d..0000000
--- a/src/Redux.Sandbox.Universal/CounterReducer.cs
+++ /dev/null
@@ -1,20 +0,0 @@
-namespace Redux.Sandbox.Universal
-{
-    public static class CounterReducer
-    {
-        public static int Execute(int previousState, IAction action)
-        {
-            if (action is IncrementAction)
-            {
-                return previousState + 1;
-            }
-
-            if (action is DecrementAction)
-            {
-                return previousState - 1;
-            }
-
-            return previousState;
-        }
-    }
-}
diff --git a/src/Redux.Sandbox.Universal/MainPage.xaml b/src/Redux.Sandbox.Universal/MainPage.xaml
deleted file mode 100644
index c1e53ee..0000000
--- a/src/Redux.Sandbox.Universal/MainPage.xaml
+++ /dev/null
@@ -1,30 +0,0 @@
-<Page
-    x:Class="Redux.Sandbox.Universal.MainPage"
-    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
-    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-    xmlns:local="using:Redux.Sandbox.Universal"
-    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
-    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
-    mc:Ignorable="d">
-
-    <StackPanel Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
-        <TextBlock>
-            <Run Text="Clicked: "/>
-            <Run x:Name="CounterRun"/>
-            <Run Text=" times"/>
-        </TextBlock>
-        <Button 
-            Content="+"
-            Click="IncrementButton_Click"/>
-        <Button 
-            Content="-"
-            Click="DecrementButton_Click"/>
-        <Button
-            Content="Increment if odd"
-            Click="IncrementIfOddButton_Click"/>
-        <Button
-            Content="Increment async"
-            Click="IncrementAsyncButton_Click"/>
-    </StackPanel>
-
-</Page>
diff --git a/src/Redux.Sandbox.Universal/MainPage.xaml.cs b/src/Redux.Sandbox.Universal/MainPage.xaml.cs
deleted file mode 100644
index 6672271..0000000
--- a/src/Redux.Sandbox.Universal/MainPage.xaml.cs
+++ /dev/null
@@ -1,43 +0,0 @@
-using Windows.UI.Xaml.Controls;
-using System;
-using System.Threading.Tasks;
-using System.Reactive.Linq;
-
-namespace Redux.Sandbox.Universal
-{
-    public sealed partial class MainPage : Page
-    {
-
-        public MainPage()
-        {
-            this.InitializeComponent();
-
-            App.CounterStore.Subscribe(counter => CounterRun.Text = counter.ToString());
-        }
-
-        private void IncrementButton_Click(object sender, Windows.UI.Xaml.RoutedEventArgs e)
-        {
-            App.CounterStore.Dispatch(new IncrementAction());
-        }
-
-        private void DecrementButton_Click(object sender, Windows.UI.Xaml.RoutedEventArgs e)
-        {
-            App.CounterStore.Dispatch(new DecrementAction());
-        }
-
-        private async void IncrementIfOddButton_Click(object sender, Windows.UI.Xaml.RoutedEventArgs e)
-        {
-            var counter = await App.CounterStore.FirstAsync();
-            if (counter % 2 == 1)
-            {
-                App.CounterStore.Dispatch(new IncrementAction());
-            }
-        }
-
-        private async void IncrementAsyncButton_Click(object sender, Windows.UI.Xaml.RoutedEventArgs e)
-        {
-            await Task.Delay(1000);
-            App.CounterStore.Dispatch(new IncrementAction());
-        }
-    }
-}
diff --git a/src/Redux.Sandbox.Universal/Package.appxmanifest b/src/Redux.Sandbox.Universal/Package.appxmanifest
deleted file mode 100644
index 7f6270b..0000000
--- a/src/Redux.Sandbox.Universal/Package.appxmanifest
+++ /dev/null
@@ -1,49 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-
-<Package
-  xmlns="http://schemas.microsoft.com/appx/manifest/foundation/windows10"
-  xmlns:mp="http://schemas.microsoft.com/appx/2014/phone/manifest"
-  xmlns:uap="http://schemas.microsoft.com/appx/manifest/uap/windows10"
-  IgnorableNamespaces="uap mp">
-
-  <Identity
-    Name="f6df710c-4570-4993-bc18-b973eb1e67fb"
-    Publisher="CN=Guillaume"
-    Version="1.0.0.0" />
-
-  <mp:PhoneIdentity PhoneProductId="f6df710c-4570-4993-bc18-b973eb1e67fb" PhonePublisherId="00000000-0000-0000-0000-000000000000"/>
-
-  <Properties>
-    <DisplayName>Redux.Sandbox.Universal</DisplayName>
-    <PublisherDisplayName>Guillaume</PublisherDisplayName>
-    <Logo>Assets\StoreLogo.png</Logo>
-  </Properties>
-
-  <Dependencies>
-    <TargetDeviceFamily Name="Windows.Universal" MinVersion="10.0.0.0" MaxVersionTested="10.0.0.0" />
-  </Dependencies>
-
-  <Resources>
-    <Resource Language="x-generate"/>
-  </Resources>
-
-  <Applications>
-    <Application Id="App"
-      Executable="$targetnametoken$.exe"
-      EntryPoint="Redux.Sandbox.Universal.App">
-      <uap:VisualElements
-        DisplayName="Redux.Sandbox.Universal"
-        Square150x150Logo="Assets\Square150x150Logo.png"
-        Square44x44Logo="Assets\Square44x44Logo.png"
-        Description="Redux.Sandbox.Universal"
-        BackgroundColor="transparent">
-        <uap:DefaultTile Wide310x150Logo="Assets\Wide310x150Logo.png"/>
-        <uap:SplashScreen Image="Assets\SplashScreen.png" />
-      </uap:VisualElements>
-    </Application>
-  </Applications>
-
-  <Capabilities>
-    <Capability Name="internetClient" />
-  </Capabilities>
-</Package>
\ No newline at end of file
diff --git a/src/Redux.Sandbox.Universal/Properties/Default.rd.xml b/src/Redux.Sandbox.Universal/Properties/Default.rd.xml
deleted file mode 100644
index 461bc4c..0000000
--- a/src/Redux.Sandbox.Universal/Properties/Default.rd.xml
+++ /dev/null
@@ -1,31 +0,0 @@
-<!--
-    This file contains Runtime Directives used by .NET Native. The defaults here are suitable for most
-    developers. However, you can modify these parameters to modify the behavior of the .NET Native
-    optimizer.
-
-    Runtime Directives are documented at http://go.microsoft.com/fwlink/?LinkID=391919
-
-    To fully enable reflection for App1.MyClass and all of its public/private members
-    <Type Name="App1.MyClass" Dynamic="Required All"/>
-
-    To enable dynamic creation of the specific instantiation of AppClass<T> over System.Int32
-    <TypeInstantiation Name="App1.AppClass" Arguments="System.Int32" Activate="Required Public" />
-
-    Using the Namespace directive to apply reflection policy to all the types in a particular namespace
-    <Namespace Name="DataClasses.ViewModels" Seralize="All" />
--->
-
-<Directives xmlns="http://schemas.microsoft.com/netfx/2013/01/metadata">
-  <Application>
-    <!--
-      An Assembly element with Name="*Application*" applies to all assemblies in
-      the application package. The asterisks are not wildcards.
-    -->
-    <Assembly Name="*Application*" Dynamic="Required All" />
-    
-    
-    <!-- Add your application specific runtime directives here. -->
-
-
-  </Application>
-</Directives>
\ No newline at end of file
diff --git a/src/Redux.Sandbox.Universal/Redux.Sandbox.Universal.csproj b/src/Redux.Sandbox.Universal/Redux.Sandbox.Universal.csproj
deleted file mode 100644
index 475dbf2..0000000
--- a/src/Redux.Sandbox.Universal/Redux.Sandbox.Universal.csproj
+++ /dev/null
@@ -1,153 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">x86</Platform>
-    <ProjectGuid>{EB423034-9A33-4F85-B5D2-BE5E44C184AE}</ProjectGuid>
-    <OutputType>AppContainerExe</OutputType>
-    <AppDesignerFolder>Properties</AppDesignerFolder>
-    <RootNamespace>Redux.Sandbox.Universal</RootNamespace>
-    <AssemblyName>Redux.Sandbox.Universal</AssemblyName>
-    <DefaultLanguage>en-US</DefaultLanguage>
-    <TargetPlatformIdentifier>UAP</TargetPlatformIdentifier>
-    <TargetPlatformVersion>10.0.10240.0</TargetPlatformVersion>
-    <TargetPlatformMinVersion>10.0.10240.0</TargetPlatformMinVersion>
-    <MinimumVisualStudioVersion>14</MinimumVisualStudioVersion>
-    <EnableDotNetNativeCompatibleProfile>true</EnableDotNetNativeCompatibleProfile>
-    <FileAlignment>512</FileAlignment>
-    <ProjectTypeGuids>{A5A43C5B-DE2A-4C0C-9213-0A381AF9435A};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}</ProjectTypeGuids>
-    <PackageCertificateKeyFile>Redux.Sandbox.Universal_TemporaryKey.pfx</PackageCertificateKeyFile>
-  </PropertyGroup>
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|ARM'">
-    <DebugSymbols>true</DebugSymbols>
-    <OutputPath>bin\ARM\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE;NETFX_CORE;WINDOWS_UWP</DefineConstants>
-    <NoWarn>;2008</NoWarn>
-    <DebugType>full</DebugType>
-    <PlatformTarget>ARM</PlatformTarget>
-    <UseVSHostingProcess>false</UseVSHostingProcess>
-    <ErrorReport>prompt</ErrorReport>
-    <Prefer32Bit>true</Prefer32Bit>
-  </PropertyGroup>
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Release|ARM'">
-    <OutputPath>bin\ARM\Release\</OutputPath>
-    <DefineConstants>TRACE;NETFX_CORE;WINDOWS_UWP</DefineConstants>
-    <Optimize>true</Optimize>
-    <NoWarn>;2008</NoWarn>
-    <DebugType>pdbonly</DebugType>
-    <PlatformTarget>ARM</PlatformTarget>
-    <UseVSHostingProcess>false</UseVSHostingProcess>
-    <ErrorReport>prompt</ErrorReport>
-    <Prefer32Bit>true</Prefer32Bit>
-    <UseDotNetNativeToolchain>true</UseDotNetNativeToolchain>
-  </PropertyGroup>
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|x64'">
-    <DebugSymbols>true</DebugSymbols>
-    <OutputPath>bin\x64\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE;NETFX_CORE;WINDOWS_UWP</DefineConstants>
-    <NoWarn>;2008</NoWarn>
-    <DebugType>full</DebugType>
-    <PlatformTarget>x64</PlatformTarget>
-    <UseVSHostingProcess>false</UseVSHostingProcess>
-    <ErrorReport>prompt</ErrorReport>
-    <Prefer32Bit>true</Prefer32Bit>
-  </PropertyGroup>
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Release|x64'">
-    <OutputPath>bin\x64\Release\</OutputPath>
-    <DefineConstants>TRACE;NETFX_CORE;WINDOWS_UWP</DefineConstants>
-    <Optimize>true</Optimize>
-    <NoWarn>;2008</NoWarn>
-    <DebugType>pdbonly</DebugType>
-    <PlatformTarget>x64</PlatformTarget>
-    <UseVSHostingProcess>false</UseVSHostingProcess>
-    <ErrorReport>prompt</ErrorReport>
-    <Prefer32Bit>true</Prefer32Bit>
-    <UseDotNetNativeToolchain>true</UseDotNetNativeToolchain>
-  </PropertyGroup>
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|x86'">
-    <DebugSymbols>true</DebugSymbols>
-    <OutputPath>bin\x86\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE;NETFX_CORE;WINDOWS_UWP</DefineConstants>
-    <NoWarn>;2008</NoWarn>
-    <DebugType>full</DebugType>
-    <PlatformTarget>x86</PlatformTarget>
-    <UseVSHostingProcess>false</UseVSHostingProcess>
-    <ErrorReport>prompt</ErrorReport>
-    <Prefer32Bit>true</Prefer32Bit>
-  </PropertyGroup>
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Release|x86'">
-    <OutputPath>bin\x86\Release\</OutputPath>
-    <DefineConstants>TRACE;NETFX_CORE;WINDOWS_UWP</DefineConstants>
-    <Optimize>true</Optimize>
-    <NoWarn>;2008</NoWarn>
-    <DebugType>pdbonly</DebugType>
-    <PlatformTarget>x86</PlatformTarget>
-    <UseVSHostingProcess>false</UseVSHostingProcess>
-    <ErrorReport>prompt</ErrorReport>
-    <Prefer32Bit>true</Prefer32Bit>
-    <UseDotNetNativeToolchain>true</UseDotNetNativeToolchain>
-  </PropertyGroup>
-  <ItemGroup>
-    <!-- A reference to the entire .Net Framework and Windows SDK are automatically included -->
-    <None Include="project.json" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="App.xaml.cs">
-      <DependentUpon>App.xaml</DependentUpon>
-    </Compile>
-    <Compile Include="CounterActions.cs" />
-    <Compile Include="CounterReducer.cs" />
-    <Compile Include="MainPage.xaml.cs">
-      <DependentUpon>MainPage.xaml</DependentUpon>
-    </Compile>
-    <Compile Include="Properties\AssemblyInfo.cs" />
-  </ItemGroup>
-  <ItemGroup>
-    <AppxManifest Include="Package.appxmanifest">
-      <SubType>Designer</SubType>
-    </AppxManifest>
-    <None Include="Redux.Sandbox.Universal_TemporaryKey.pfx" />
-  </ItemGroup>
-  <ItemGroup>
-    <Content Include="Properties\Default.rd.xml" />
-    <Content Include="Assets\LockScreenLogo.scale-200.png" />
-    <Content Include="Assets\SplashScreen.scale-200.png" />
-    <Content Include="Assets\Square150x150Logo.scale-200.png" />
-    <Content Include="Assets\Square44x44Logo.scale-200.png" />
-    <Content Include="Assets\Square44x44Logo.targetsize-24_altform-unplated.png" />
-    <Content Include="Assets\StoreLogo.png" />
-    <Content Include="Assets\Wide310x150Logo.scale-200.png" />
-  </ItemGroup>
-  <ItemGroup>
-    <ApplicationDefinition Include="App.xaml">
-      <Generator>MSBuild:Compile</Generator>
-      <SubType>Designer</SubType>
-    </ApplicationDefinition>
-    <Page Include="MainPage.xaml">
-      <Generator>MSBuild:Compile</Generator>
-      <SubType>Designer</SubType>
-    </Page>
-  </ItemGroup>
-  <ItemGroup>
-    <ProjectReference Include="..\Redux.DevTools.Universal\Redux.DevTools.Universal.csproj">
-      <Project>{9e9e1f17-990b-4208-8bb6-4b2f5e295ee9}</Project>
-      <Name>Redux.DevTools.Universal</Name>
-    </ProjectReference>
-    <ProjectReference Include="..\Redux\Redux.csproj">
-      <Project>{a15d3f17-691f-48df-9078-27dcde7141eb}</Project>
-      <Name>Redux</Name>
-    </ProjectReference>
-  </ItemGroup>
-  <PropertyGroup Condition=" '$(VisualStudioVersion)' == '' or '$(VisualStudioVersion)' &lt; '14.0' ">
-    <VisualStudioVersion>14.0</VisualStudioVersion>
-  </PropertyGroup>
-  <Import Project="$(MSBuildExtensionsPath)\Microsoft\WindowsXaml\v$(VisualStudioVersion)\Microsoft.Windows.UI.Xaml.CSharp.targets" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
-</Project>
\ No newline at end of file
diff --git a/src/Redux.Sandbox.Universal/project.json b/src/Redux.Sandbox.Universal/project.json
deleted file mode 100644
index 5732938..0000000
--- a/src/Redux.Sandbox.Universal/project.json
+++ /dev/null
@@ -1,17 +0,0 @@
-{
-  "dependencies": {
-    "Microsoft.NETCore.UniversalWindowsPlatform": "5.0.0",
-    "Rx-Main": "2.2.5"
-  },
-  "frameworks": {
-    "uap10.0": {}
-  },
-  "runtimes": {
-    "win10-arm": {},
-    "win10-arm-aot": {},
-    "win10-x86": {},
-    "win10-x86-aot": {},
-    "win10-x64": {},
-    "win10-x64-aot": {}
-  }
-}
\ No newline at end of file
diff --git a/src/Redux.Tests/FakeAction.cs b/src/Redux.Tests/FakeAction.cs
new file mode 100644
index 0000000..89ed9d1
--- /dev/null
+++ b/src/Redux.Tests/FakeAction.cs
@@ -0,0 +1,12 @@
+namespace Redux.Tests
+{
+    public class FakeAction<T> : IAction
+    {
+        public T Value { get; set; }
+
+        public FakeAction(T value)
+        {
+            Value = value;
+        }
+    }
+}
diff --git a/src/Redux.Tests/MockObserver.cs b/src/Redux.Tests/MockObserver.cs
new file mode 100644
index 0000000..88a4a47
--- /dev/null
+++ b/src/Redux.Tests/MockObserver.cs
@@ -0,0 +1,30 @@
+using System;
+using System.Collections.Generic;
+
+namespace Redux.Tests
+{
+    public class MockObserver<T> : IObserver<T>
+    {
+        public bool IsCompleted { get; private set; }
+
+        public Exception Error { get; private set; }
+
+        private readonly List<T> _values = new List<T>();
+        public IEnumerable<T> Values => _values;
+
+        public void OnCompleted()
+        {
+            IsCompleted = true;
+        }
+
+        public void OnError(Exception error)
+        {
+            Error = error;
+        }
+
+        public void OnNext(T value)
+        {
+            _values.Add(value);
+        }
+    }
+}
diff --git a/src/Redux.Sandbox.Universal/Properties/AssemblyInfo.cs b/src/Redux.Tests/Properties/AssemblyInfo.cs
similarity index 64%
rename from src/Redux.Sandbox.Universal/Properties/AssemblyInfo.cs
rename to src/Redux.Tests/Properties/AssemblyInfo.cs
index 91fc54d..2406304 100644
--- a/src/Redux.Sandbox.Universal/Properties/AssemblyInfo.cs
+++ b/src/Redux.Tests/Properties/AssemblyInfo.cs
@@ -5,15 +5,23 @@
 // General Information about an assembly is controlled through the following 
 // set of attributes. Change these attribute values to modify the information
 // associated with an assembly.
-[assembly: AssemblyTitle("Redux.Sandbox.Universal")]
+[assembly: AssemblyTitle("Redux.Tests")]
 [assembly: AssemblyDescription("")]
 [assembly: AssemblyConfiguration("")]
 [assembly: AssemblyCompany("")]
-[assembly: AssemblyProduct("Redux.Sandbox.Universal")]
+[assembly: AssemblyProduct("Redux.Tests")]
 [assembly: AssemblyCopyright("Copyright ©  2015")]
 [assembly: AssemblyTrademark("")]
 [assembly: AssemblyCulture("")]
 
+// Setting ComVisible to false makes the types in this assembly not visible 
+// to COM components.  If you need to access a type in this assembly from 
+// COM, set the ComVisible attribute to true on that type.
+[assembly: ComVisible(false)]
+
+// The following GUID is for the ID of the typelib if this project is exposed to COM
+[assembly: Guid("41c1eeba-4cd2-4158-b5c0-d091233db419")]
+
 // Version information for an assembly consists of the following four values:
 //
 //      Major Version
@@ -26,4 +34,3 @@
 // [assembly: AssemblyVersion("1.0.*")]
 [assembly: AssemblyVersion("1.0.0.0")]
 [assembly: AssemblyFileVersion("1.0.0.0")]
-[assembly: ComVisible(false)]
\ No newline at end of file
diff --git a/src/Redux.Tests/Reducers.cs b/src/Redux.Tests/Reducers.cs
new file mode 100644
index 0000000..ac458d5
--- /dev/null
+++ b/src/Redux.Tests/Reducers.cs
@@ -0,0 +1,22 @@
+namespace Redux.Tests
+{
+    public static class Reducers
+    {
+        public static TState PassThrough<TState>(TState previousState, IAction action)
+        {
+            return previousState;
+        }
+
+        public static TState Replace<TState>(TState previousState, IAction action)
+        {
+            var fakeAction = action as FakeAction<TState>;
+
+            if(fakeAction != null)
+            {
+                return fakeAction.Value;
+            }
+
+            return previousState;
+        }
+    }
+}
diff --git a/src/Redux.Tests/Redux.Tests.csproj b/src/Redux.Tests/Redux.Tests.csproj
new file mode 100644
index 0000000..b528146
--- /dev/null
+++ b/src/Redux.Tests/Redux.Tests.csproj
@@ -0,0 +1,105 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <ProjectGuid>{41C1EEBA-4CD2-4158-B5C0-D091233DB419}</ProjectGuid>
+    <OutputType>Library</OutputType>
+    <AppDesignerFolder>Properties</AppDesignerFolder>
+    <RootNamespace>Redux.Tests</RootNamespace>
+    <AssemblyName>Redux.Tests</AssemblyName>
+    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
+    <FileAlignment>512</FileAlignment>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
+    <DebugSymbols>true</DebugSymbols>
+    <DebugType>full</DebugType>
+    <Optimize>false</Optimize>
+    <OutputPath>bin\Debug\</OutputPath>
+    <DefineConstants>DEBUG;TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
+    <DebugType>pdbonly</DebugType>
+    <Optimize>true</Optimize>
+    <OutputPath>bin\Release\</OutputPath>
+    <DefineConstants>TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <ItemGroup>
+    <Reference Include="nunit.core, Version=2.6.4.14350, Culture=neutral, PublicKeyToken=96d09a1eb7f44a77, processorArchitecture=MSIL">
+      <HintPath>..\packages\NUnitTestAdapter.2.0.0\lib\nunit.core.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
+    <Reference Include="nunit.core.interfaces, Version=2.6.4.14350, Culture=neutral, PublicKeyToken=96d09a1eb7f44a77, processorArchitecture=MSIL">
+      <HintPath>..\packages\NUnitTestAdapter.2.0.0\lib\nunit.core.interfaces.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
+    <Reference Include="nunit.framework, Version=2.6.4.14350, Culture=neutral, PublicKeyToken=96d09a1eb7f44a77, processorArchitecture=MSIL">
+      <HintPath>..\packages\NUnit.2.6.4\lib\nunit.framework.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
+    <Reference Include="nunit.util, Version=2.6.4.14350, Culture=neutral, PublicKeyToken=96d09a1eb7f44a77, processorArchitecture=MSIL">
+      <HintPath>..\packages\NUnitTestAdapter.2.0.0\lib\nunit.util.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
+    <Reference Include="NUnit.VisualStudio.TestAdapter, Version=2.0.0.0, Culture=neutral, PublicKeyToken=4cb40d35494691ac, processorArchitecture=MSIL">
+      <HintPath>..\packages\NUnitTestAdapter.2.0.0\lib\NUnit.VisualStudio.TestAdapter.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
+    <Reference Include="System" />
+    <Reference Include="System.Core" />
+    <Reference Include="System.Reactive.Core, Version=2.2.5.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL">
+      <HintPath>..\packages\Rx-Core.2.2.5\lib\net45\System.Reactive.Core.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
+    <Reference Include="System.Reactive.Interfaces, Version=2.2.5.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL">
+      <HintPath>..\packages\Rx-Interfaces.2.2.5\lib\net45\System.Reactive.Interfaces.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
+    <Reference Include="System.Reactive.Linq, Version=2.2.5.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL">
+      <HintPath>..\packages\Rx-Linq.2.2.5\lib\net45\System.Reactive.Linq.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
+    <Reference Include="System.Reactive.PlatformServices, Version=2.2.5.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL">
+      <HintPath>..\packages\Rx-PlatformServices.2.2.5\lib\net45\System.Reactive.PlatformServices.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
+    <Reference Include="System.Xml.Linq" />
+    <Reference Include="System.Data.DataSetExtensions" />
+    <Reference Include="Microsoft.CSharp" />
+    <Reference Include="System.Data" />
+    <Reference Include="System.Net.Http" />
+    <Reference Include="System.Xml" />
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="FakeAction.cs" />
+    <Compile Include="Reducers.cs" />
+    <Compile Include="StoreTests.cs" />
+    <Compile Include="MockObserver.cs" />
+    <Compile Include="Properties\AssemblyInfo.cs" />
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="packages.config" />
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\Redux\Redux.csproj">
+      <Project>{a15d3f17-691f-48df-9078-27dcde7141eb}</Project>
+      <Name>Redux</Name>
+    </ProjectReference>
+  </ItemGroup>
+  <ItemGroup>
+    <Service Include="{82A7F48D-3B50-4B1E-B82E-3ADA8210C358}" />
+  </ItemGroup>
+  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
+  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
+       Other similar extension points exist, see Microsoft.Common.targets.
+  <Target Name="BeforeBuild">
+  </Target>
+  <Target Name="AfterBuild">
+  </Target>
+  -->
+</Project>
\ No newline at end of file
diff --git a/src/Redux.Tests/StoreTests.cs b/src/Redux.Tests/StoreTests.cs
new file mode 100644
index 0000000..5728851
--- /dev/null
+++ b/src/Redux.Tests/StoreTests.cs
@@ -0,0 +1,44 @@
+using NUnit.Core;
+using NUnit.Framework;
+
+namespace Redux.Tests
+{
+    [TestFixture]
+    public class StoreTests
+    {
+        [Test]
+        public void Should_push_initial_state()
+        {
+            var sut = new Store<int>(1, Reducers.PassThrough);
+            var mockObserver = new MockObserver<int>();
+
+            sut.Subscribe(mockObserver);
+
+            CollectionAssert.AreEqual(new[] { 1 }, mockObserver.Values);
+        }
+
+        [Test]
+        public void Should_push_state_on_dispatch()
+        {
+            var sut = new Store<int>(1, Reducers.Replace);
+            var mockObserver = new MockObserver<int>();
+
+            sut.Subscribe(mockObserver);
+            sut.Dispatch(new FakeAction<int>(2));
+
+            CollectionAssert.AreEqual(new[] { 1, 2 }, mockObserver.Values);
+        }
+
+        [Test]
+        public void Should_only_push_the_last_state_before_subscription()
+        {
+            var sut = new Store<int>(1, Reducers.Replace);
+            var mockObserver = new MockObserver<int>();
+
+            sut.Dispatch(new FakeAction<int>(2));
+            sut.Subscribe(mockObserver);
+
+            CollectionAssert.AreEqual(new[] { 2 }, mockObserver.Values);
+        }
+    }
+}
diff --git a/src/Redux.Tests/packages.config b/src/Redux.Tests/packages.config
new file mode 100644
index 0000000..87421ea
--- /dev/null
+++ b/src/Redux.Tests/packages.config
@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<packages>
+  <package id="NUnit" version="2.6.4" targetFramework="net45" />
+  <package id="NUnitTestAdapter" version="2.0.0" targetFramework="net45" />
+  <package id="Rx-Core" version="2.2.5" targetFramework="net45" />
+  <package id="Rx-Interfaces" version="2.2.5" targetFramework="net45" />
+  <package id="Rx-Linq" version="2.2.5" targetFramework="net45" />
+  <package id="Rx-Main" version="2.2.5" targetFramework="net45" />
+  <package id="Rx-PlatformServices" version="2.2.5" targetFramework="net45" />
+</packages>
\ No newline at end of file
diff --git a/src/Redux.sln b/src/Redux.sln
index cfc26b5..a60661e 100644
--- a/src/Redux.sln
+++ b/src/Redux.sln
@@ -7,7 +7,7 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Redux", "Redux\Redux.csproj
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Redux.DevTools.Universal", "Redux.DevTools.Universal\Redux.DevTools.Universal.csproj", "{9E9E1F17-990B-4208-8BB6-4B2F5E295EE9}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Redux.Sandbox.Universal", "Redux.Sandbox.Universal\Redux.Sandbox.Universal.csproj", "{EB423034-9A33-4F85-B5D2-BE5E44C184AE}"
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Redux.Tests", "Redux.Tests\Redux.Tests.csproj", "{41C1EEBA-4CD2-4158-B5C0-D091233DB419}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -53,28 +53,22 @@ Global
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-		{EB423034-9A33-4F85-B5D2-BE5E44C184AE}.Debug|Any CPU.ActiveCfg = Debug|x86
-		{EB423034-9A33-4F85-B5D2-BE5E44C184AE}.Debug|Any CPU.Build.0 = Debug|x86
-		{EB423034-9A33-4F85-B5D2-BE5E44C184AE}.Debug|Any CPU.Deploy.0 = Debug|x86
-		{EB423034-9A33-4F85-B5D2-BE5E44C184AE}.Debug|ARM.ActiveCfg = Debug|ARM
-		{EB423034-9A33-4F85-B5D2-BE5E44C184AE}.Debug|ARM.Build.0 = Debug|ARM
-		{EB423034-9A33-4F85-B5D2-BE5E44C184AE}.Debug|ARM.Deploy.0 = Debug|ARM
-		{EB423034-9A33-4F85-B5D2-BE5E44C184AE}.Debug|x64.ActiveCfg = Debug|x64
-		{EB423034-9A33-4F85-B5D2-BE5E44C184AE}.Debug|x64.Build.0 = Debug|x64
-		{EB423034-9A33-4F85-B5D2-BE5E44C184AE}.Debug|x64.Deploy.0 = Debug|x64
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-		{EB423034-9A33-4F85-B5D2-BE5E44C184AE}.Debug|x86.Build.0 = Debug|x86
-		{EB423034-9A33-4F85-B5D2-BE5E44C184AE}.Debug|x86.Deploy.0 = Debug|x86
-		{EB423034-9A33-4F85-B5D2-BE5E44C184AE}.Release|Any CPU.ActiveCfg = Release|x86
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-		{EB423034-9A33-4F85-B5D2-BE5E44C184AE}.Release|ARM.Build.0 = Release|ARM
-		{EB423034-9A33-4F85-B5D2-BE5E44C184AE}.Release|ARM.Deploy.0 = Release|ARM
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-		{EB423034-9A33-4F85-B5D2-BE5E44C184AE}.Release|x86.Build.0 = Release|x86
-		{EB423034-9A33-4F85-B5D2-BE5E44C184AE}.Release|x86.Deploy.0 = Release|x86
+		{41C1EEBA-4CD2-4158-B5C0-D091233DB419}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{41C1EEBA-4CD2-4158-B5C0-D091233DB419}.Debug|Any CPU.Build.0 = Debug|Any CPU
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+		{41C1EEBA-4CD2-4158-B5C0-D091233DB419}.Debug|ARM.Build.0 = Debug|Any CPU
+		{41C1EEBA-4CD2-4158-B5C0-D091233DB419}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{41C1EEBA-4CD2-4158-B5C0-D091233DB419}.Debug|x64.Build.0 = Debug|Any CPU
+		{41C1EEBA-4CD2-4158-B5C0-D091233DB419}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{41C1EEBA-4CD2-4158-B5C0-D091233DB419}.Debug|x86.Build.0 = Debug|Any CPU
+		{41C1EEBA-4CD2-4158-B5C0-D091233DB419}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{41C1EEBA-4CD2-4158-B5C0-D091233DB419}.Release|Any CPU.Build.0 = Release|Any CPU
+		{41C1EEBA-4CD2-4158-B5C0-D091233DB419}.Release|ARM.ActiveCfg = Release|Any CPU
+		{41C1EEBA-4CD2-4158-B5C0-D091233DB419}.Release|ARM.Build.0 = Release|Any CPU
+		{41C1EEBA-4CD2-4158-B5C0-D091233DB419}.Release|x64.ActiveCfg = Release|Any CPU
+		{41C1EEBA-4CD2-4158-B5C0-D091233DB419}.Release|x64.Build.0 = Release|Any CPU
+		{41C1EEBA-4CD2-4158-B5C0-D091233DB419}.Release|x86.ActiveCfg = Release|Any CPU
+		{41C1EEBA-4CD2-4158-B5C0-D091233DB419}.Release|x86.Build.0 = Release|Any CPU
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 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE