Honestly, there's very little worth paying for (for me anyways - everyone has different wants/needs).
99% of the time on my phone is spent in one of a few apps: Browser, Facebook, Twitter, Gmail, Google Music, Google Maps, Tapatalk, and Doggcatcher.
Only the last two cost money. Both were only a few bucks and were bought years ago. Don't get me wrong I love my smartphone and spend a ton of time using it - I just have never been fascinated with the bazillion "apps" out there.