I’m using this all the time myself. There is no login to YouTube required and it supports adding subscriptions and doing everything important you can do on YouTube.
You are not logged in. However you can subscribe from another Fediverse account, for example Lemmy or Mastodon. To do this, paste the following into the search field of your instance: !piracy@lemmy.dbzer0.com
⚓ Dedicated to the discussion of digital piracy, including ethical problems and legal advancements.
There is also an Android fork which works amazingly well.
is this on their git or fdroid by chance?
Here.