This feature would let you play certain games with your Twitch viewers by allowing those playing to take turns controlling the streamer's keyboard.
This feature would be universal to all games that rely on simple keyboard inputs (ie Blackjack, etc.)
How it Works:
Streamer creates a list of users who are playing, and custom commands depending on the game being played.
Ex. in Blackjack, when a player's turn comes, the selected player types "!hit", chatbot execuses a keyboard press 'H', which is the shortcut for hit)
When user is done with their turn, they type !end, and control shifts to the next user in the list.
Essentially, there'd be no limits to how many can play except constraints placed by the game you are playing.
There could also be a 'Full Chat' feature that surveys the Streamers entire chat and actuates the command most typed, a la "Twitch plays".