Reddit blocked third party apps but they didn't block personal-use API access. With the help of some apk-editing tools that I won't mention here, you could import your own API key into a third party apps and continue using it fully (including posting and commenting). I'm using Reddit Sync still.

My API key still works, but my understanding is Reddit recently blocked the generation of new keys. So at some point my key will probably die too. At that point, that's the end of Reddit for me.

On android you can using redreader for free. I'm still using it for anonim read only reddit

Hydra works really well on iOS. It's not read only, full usage.

And it behaves and looks really similar to the Lemmy client I use (Voyager). Unsure if they share some of the codebase or if they both just try to imitate Apollo.

The main change was them charging for the API so you can simply make a developer API key for free and patch it into apps. I'm using Boost and it still works well.

AFAIK there are a few, “read only” apps. iOS has RDX, not sure about Android.

I think there are still "read-only" clients. I haven't looked in awhile, but I know there were some available via F-Droid (alternative app store) long after the API was cut off. I assume they use standard web scraping for grabbing content.

Also, I'm not sure if it still works, but I think you can still use open source clients that rely on the API, you just have to compile/build them yourself using your account's own personal API key.

I haven't looked into either of these in a while and definitely not an expert on the topic, but I'm sure if you're interested there's enough info out there to find a solution that works for you.