I would focus on making the best Reddit macOS app you can, that will likely be your largest and most receptive audience. You should use the Apollo iOS app as your benchmark as far as responsiveness and feature set is concerned.

I signed up for the beta, the most glaring omissions are:

1. Keyboard shortcuts. You'll probably want to implement arrow key navigation as well as Google Reader shortcuts (J=Next, K=Previous, see Reeder.app). RES is the gold standard you should be shooting for: http://joeross.me/res/

2. Expand at least a few levels of child comments by default. Apollo does a great job with this.

3. Remove avatar placeholders for services that do not have avatars.

4. Increase information density. In the same vertical space that I can see 14 posts on reddit.com, I can only see 10 in the compact view in your app. The comments are in worse shape, you must remove the spacing between the comment "cards".

Overall, I'm impressed with what you've built here and could see using this app. Keyboard shortcuts are a must before I would spend any significant time using it.