For over a year, I had been using the Feed Me feed reader on android to connect to my TinyTinyRSS installation. Unfortunately, it has been acting up in the past month, unable to sync some categories, sometimes not getting new articles for days even though it said it synchronized fine.
Today I found this app, which is open source and installable via fdroid 💯. So far, it works well, has all the features (offline mode, mark read on scroll, etc.), a decent interface, and is fast!