This app was mentioned in 2 comments, with an average of 3.00 upvotes
Please think of this as a similar experience to watching the stream on dedicated Android app.
I don't want to decrease Steven's revenue – if anything, it could only increase it. The player will still be able to display Twitch ads, and embedded chat will display all subscribers' perks. If the final reception of this idea will be positive, and I'll end up making it, I could even add links to become a sub (Twitch or Destiny.gg) right from the app and he'd keep all the profits.
As to switching between chats – some people watch/discover him via Twitch, and some like to follow both chats at once. Keeping the Twitch subscriber base above 400 is an important thing from the Destiny–Twitch business relationship standpoint.
https://play.google.com/store/apps/details?id=gg.destiny.app.chat&hl=en
I don't think 9inevolt still updates it though.