You can create new functionality for the HEXA robot by creating Skills. A skill is simply a HEXA application packaged as an .mpk file containing a directory structure as specified below.
myskill
├── manifest.json
├── remote
│ ├── assets
│ │ ├── myskill.js
│ │ └── style.css
│ └── index.html
└── robot
├── deps
├── assets
└── src
└── myskill.go
There are two main folders that you need: remote and robot, which refer to the two parts of the MIND SDK.
In addition, you'll also need a manifest.json file to contain metadata about your application.