we all know that there's no first level inter-app communication support in iOS. Gruber has put it recently on his fanboy blog:
"What else remains hanging low on the iOS new-features tree, though? I can think of a few:
Clever inter-application communication. Seems crazy that iOS, the direct descendant of NeXT, doesn’t have anything like Services, which were one of NeXT’s most touted features (and rightfully so). It’s also worth noting that Android has a pretty good Services-esque system in place, called “Intents”, and Windows 8 has an even richer concept called “Contracts”."