Multistream for Android

Free, no account needed.

The same Multistream, as an app for your phone. It opens this website with everything the browser extension does already built in:

Streams play in Twitch's own player at up to 1080p60 (Firefox on Android plays some of them at about 40fps).
Your watch time earns channel points; your balance shows next to the chat and bonus chests are claimed automatically.
No ads: streams load their playlist from an ad-free server (Settings → Ad blocking).
Predictions, latency reducer, audio compressor and pinch zoom.

Needs Android 11 or newer. Download the app (.apk)

Install

Download the app on your phone with the button above. If the browser warns that the file may be harmful, choose Download anyway: it says that about every app from outside Google Play.
Open the downloaded file (from the browser's notification or its downloads list).
The first time, Android asks to allow installing apps from this browser: tap Settings, turn on Allow from this source and go back.
Tap Install. If Google Play Protect asks to scan the app or says it doesn't recognize the developer, choose Install anyway (or More details → Install anyway).

First start

Log in with Twitch in Multistream, the same as on the website. If twitch.tv's own login page opens over it, log in there too: that's the session that earns channel points.
The app then opens twitch.tv/activate with a code already typed in. Tap Activate and then Authorize. This links the app once so it can claim bonus chests for you; Twitch doesn't accept them otherwise. Going back skips it (claims are then tried another way, which Twitch often ignores).

Updating

Settings → Android app tells you when there's a new version. Download it the same way and install it over the one you have: your login and settings stay.

Privacy

Your Twitch login stays inside the app and is only sent to Twitch. The Multistream website only receives balances and claim results, as with the extension. With ad blocking on, the ad-free server sees which channels you watch, but not your account.

Ad blocking and claiming as Twitch's TV app aren't allowed by Twitch's terms. Many people use apps that do the same (PurpleTV, the channel points miner), but Twitch could act against accounts that do.