I have released my first app on the iOS App Store a few days ago and told my friends to download it. However, they have told me that it is not compatible with the iPod Touch 2G running iOS 4.2.1. Why is this? And how do I fix this?
I am using Xcode 4.2 with iOS SDK 5.0, but my deployment target is iOS 4.0, so it should work.
On the iTunes page for my app, it says: Requirements: Compatible with iPhone 3GS, iPhone 4, iPhone 4S, iPod touch (3rd generation), iPod touch (4th generation) and iPad. Requires iOS 4.0 or later.
How do I include the iPod Touch 2G in this list? I have an iPod 3G as one of my testing devices and my app works perfectly on it.
Thanks in advance for your help,
Guvvy
The most likely cause is that you did not build for armv6. This is a common issue usually caught in debugging, but since you did not test on these devices you did not catch it.
If you want to add support for armv6 devices, like iPod touch 2nd gen & iPhone 3g, then in addition to setting your deployment target like you have done you must also:
1) Add armv6 to the Architectures field:
2) Remove armv7 from the requirements in the info.plist:
3) Test to ensure compatibility with these devices. Please do not ignore this step.
来源：https://stackoverflow.com/questions/8364021/xcode-set-compatible-devices