What would you like to?

Pick a project that interests you personally and build it. It doesn't matter if it's something that someone has already thought up and released, as this is YOUR project that YOU want to create.

My first app was a parking application for my local city that shows people where all the restricted parking zones are and where they can park and when. It was a nice little project that I choose because it fulfilled a need that I had and I figured that if I needed an app for that, then chances are someone else would too.

I learned a lot about Apple's APIs, particularly Core Location and Map Kit and to implement one particular feature I even had to use a 3rd party JSON parsing library.

Sure, you may not learn how to build games this way but you WILL learn how the APis work and I can promise you that it's exceptionally satisfying to be able to polish something, stick it on the App Store and see people actually downloading and using it.