Try to use https://jesterui.github.io/ :)

It's a great idea, I even tried to contribute a chat feature to it in the past but something blocked me from it, i no longer remember what happened, lol :)

edit: oh, I remember now, lol :)

Mhh, I pushed some changes but there is a bug: For some reason, the black player does not receive old chat messages when loading the page. For the white player, it works however.