I’ve seen the app Apollo as the center of the reddit protest (it was mentioned and cited more than any other app in relevant posts). I’ve also seen many Lemmy clients in development taking inspiration from it.
As a lifetime Android user I’ve never been able to use it, and I’ve never gotten a proper answer to “why not just use the official app?” What made it different from the official application and other unofficial clients that consequently made it so popular among Redditors?
I’ve been using old.reddit since 2008, even after the onset of mobile. The normal UI aka “new reddit” is horrifying and from what I can see the app is the same. There are various features missing in the new web interface as well as various situations where it restricts or lies to you, such as if you’re not signed in and it’s “mature content” or “unreviewed content” and it won’t let you view it - then go to old.reddit and you can view it with no difficulty. But anyway the writing is on the wall that they’re not going to support that interface forever, so might as well give up now.