Oh, please don't do this:

"Historically, these features [vote ups and comments] are hard to use on small devices and I want to make an app that is easy to use."

I understand that you want to make a minimal app (personal preference or laziness – doesn't really matter), but claiming that vote ups ("like buttons") are hard to use on a mobile device just makes it sound like you weren't able to build it.

It's your app, and you can do what ever you feel fit with it. There's no need to excuse your decisions with made up facts.