I only use open source apps so my choices are more limited. What I like about Eternity:
- It is stable, never experienced a crash
- Separate upvote and downvote counts
- It displays user names and instances on all posts
- Bottom drawer allows one tap access to inbox and profile
- The layout for posts is clean and have good separation between posts
- One-tap collapse / expand comments. Some other apps require tap and hold or swipe gestures.
- NSFW settings
- Notifications that actually work
- General UI design (font, spacing, icons, colours, button locations etc)
There are other apps with some of the features above, but none with all of the above.
Great. My daughter loves them.