I have my DGT Pegasus. I download the app for my android phone and it works fine with the app and with lichess. I was unable to connect to chess.com on my phone though at first. Then when I finally did it was not always registering the moves. It was fun playing other on lichess and the chess computer on liches.
I also tried connecting it to my computer and going through chess.com, but no luck. It would connect then disconnect. I finally got it saying it was connected at chess.com on the computer but it would never show any moves on the chess board. I enjoy it for what it is and how it works, just not happy with how it does not connect here as easy as I thought. I am going to keep playing around with it over time and will let you know if I have any success, meanwhile if someone know how to get it work (either the computer or the phone) with chess.com let me know.
Chessnut Air is way better than Pegasus in terms of hardware. And it has Windows driver now so that it can be used in Fritz, Lucas Chess, Shredder, HIARCS, etc. The capture bug at Pegasus is annoying. They should update the firmware.