I made a custom dashboard for openhab using the REST API. Not sure if this is the right place for this, please move it if not.
It is based on a fixed grid system and optimized to fill the entire screen. Here are some screenshots:
Pressing a Dimmer Item opens up a slider:
Pressing a Switch toggles the item.
The whole dashboard is configured using a single JSON file. You set the location of that file as well as the API base URL on the /config page. More details for setup on github.
So if anyone else wants to use it or even contribute, here is the repository: