Many have asked but I have not written a full c4 driver. I have created my own api for the kevo website. I then have integrated this into a project I run on a home server that creates connectivity for the following items:
Ryobi Garage Door Opener
Netatmo Security cameras
Hunter Douglas Shades (better than stock driver)
I then have my home server via 2 drivers in c4 interact with ui buttons and states of them and states of shades. Its not a solution that can just be moved over and installed for someone. If there was enough interest / backing for this I would be glad to convert them to drivers but for now there is no benefit for me to spend the time as it works perfectly in my solution.