I've been working on this for a while and this sub is probably the only place where people will care about the casting part as much as the games.
The TV shows the board, and anything you'd normally hide from the other players lives on your phone. In the word game your letters are on your phone. In the island trading game it's your resource cards. One person casts it from Chrome on Android or from the iPhone app, then everyone else scans a QR code on the TV to join. They don't need an account or an app.
A Chromecast thing I ran into that some of you might have seen too: Chromecast with Google TV and the Google TV Streamer would go to the screensaver in the middle of a game. disableIdleTimeout keeps the cast session alive, but the TV still decides nothing is playing and puts up the ambient photos. What finally fixed it was playing a silent 4 second video on loop behind the game. It's the same color as the background so you can't see it. Older Chromecasts never had the problem. If anyone knows a cleaner way I'd love to hear it.
There's a free demo that doesn't ask for a card. By yourself you can play chess, checkers, dominoes or sea battle against the computer, and with friends you can play a short game of the island one or the world map conquest one. The full games are paid (one-time or a small monthly subscription), but the demo is enough to see whether it works on your TV. It's also on Roku now and we're working through approval on Samsung, LG, Fire TV, and Android.
Mostly I want to hear what breaks, which TVs it doesn't work on, and what board games you'd want next.
tvtop.games