I have a 4s and it will crash occasionally, but no more often than Facebook, CNN, etc. apps do. If you can narrow it down to a specific sequence of things you do inside of the app which make it always crash then let me know because that would indicate an issue with the app itself. If it's at random, it's more than likely just an iOS thing.
I'm not necessarily saying that it's NOT the app's fault, but without something that I can replicate it's tough to diagnose.