I made a PWA of a chess clock - you can install it easily to your mobile.
Designed to be easy to use (for example, ending your turn can be done by tapping on your half of the screen - a large hit area) and clear in showing the time a player has remaining. With three modes. You can see it here:Take a look
I developed it a long time ago and there are probably lots of improvements that could be made. But it worked for what I wanted and I was pleased with how easily anyone across the world could install it to their mobile. And that it was actually useful :)
The source is here including a ‘Todo’ list that will probably never be doneBack to blog