First fully working version

Installation

1. Download camera_bookmark.py
2. In Blender, go to: Edit > Preferences > Add-ons
3. Click on Install and select the downloaded file

Usage

The add-on can be found in the N panel (under the "Camera Bookmarks" tab). You can:

1. Bookmark the current camera settings (by pressing the plus icon on the right side of the bookmark list)
2. Remove a previously saved bookmark (by pressing the minus icon)
3. Rename bookmarks (by double clicking them in the list)
4. Go to the selected bookmark (by pressing the button under the list)

Camera location, rotation and focal length are currently saved in bookmarks.