The usual rate for app crashes on iPhones is a little under 1 percent, while the rate on the iPhone 5s is closer to 2 percent.
Levy said that perhaps the reason that the iPhone 5s is seeing more crashes than the equally new iPhone 5c is that, while developers were able to check their apps for compatibility with iOS 7 during several months of beta testing, the new hardware wasn’t available ahead of time. The iPhone 5s packs a new 64-bit A7 chip and an M7 coprocessor, while the 5c is nearly identical internally to the iPhone 5 [...]
“The good news is that Apple is certainly aware of issues. they’ve pushed out two iOS updates for iOS 7… Apple is doing a really old job of addressing these issues as they come up.”