Jay from bluesky posted an update on development including the ability to uh login.

https://blueskyweb.xyz/blog/4-21-2023-atproto-developer-ecosystem

I believe that bluesky still has a single server and single set of keys for everyone. Feels like those would be a priority over say the android or iOS apps. But 🤷🏼‍♂️

Their ecosystem overview page is similar to nostr is awesome.

https://github.com/bluesky-social/atproto-ecosystem