My "go-to" app on the iPhone/Andriod for photos is VSCO Cam. I am using it since it launched. And I love it. It didn't take me too long to get used to the interface and it soon moved all the way to the first homescreen of my phone.
Well crafted filters and editing modes make it heaps of fun to play around with the snapshots I take during the day. I barely use Instagram's filters anymore. I just use it for the community and social aspect. Although they introduced "The Grid" and updated it not too long ago, its not quite there yet. Have a go if you havent checked it out yet.
And lets be friends.