It is Relay for Reddit on Android.
https://play.google.com/store/apps/details?id=free.reddit.news
The free version has ads, but they're in a banner at the bottom.
Relay has a lot of additional features, gesture-based navigation, and a nice dark theme. The only thing it runs into occassionally is Twitter links don't open properly in the built in browser because of how it accesses the Twitter API, and vreddit posts may throw it for a loop because vreddit is trash.
Hides all child comments by default, colourises them so you can follow the thread, yadda yadda. I can't stomach using Reddit any other way, except for RES on the desktop.
Play store link: Relay for reddit
It's amazing, you're gonna love it, it's the app that changed my mind about buying software, also, the first app that I bought