Tlert

Intelliborn has a reputation for making fantastic apps for jailbroken iPhones, and this one is no different. 

Having only recently been converted to the dark side, I've been frustrated by the fact that I have to choose answering texts or staying within my current app. Luckily, Tlert completely takes care of that problem for me.

The app is simple: it allows you to receive and reply to texts from any screen and within any app. This means no switching back and forth between the SMS app and everything else you were doing at the time. 

Though it does look awkward at times, depending on your screen, it is configurable and easily styled. It's also integrated with the native SMS app so that your messages will be saved regardless of where you're using them.

It works in both portrait and landscape mode too, which is nice. My only gripe is that can be tough to clear away at first, but that's easily remedied. 

Overall, this is a great app with features that should've shipped with iOS in the first place.