H.Dresden

This app, while not perfect, does a fantastic job of crunching down the numbers and streamlining games. Ive been playing in a group of several people who all have this app, and its saved us huge amounts of time. It does require you use sourcebooks not attached to the app, but for actual combat sequences and general campaigning it works very well.

That dude you might know about Fight Club PFRPG/3.5 Edition