Hello, I got your requirements and we are a professional team with availability to build an online chess in a desktop and mobile app version as we already worked on chess-based projects earlier for our clients.
I have experience with game app development using unreal unity. I develop games using HTML5, which means they work flawlessly on computers, tablets, and smartphones.
We can discuss more about the price and maybe we will do a long Relation!
With Regards,
Rohit