Is there a constant I can check to determine whether a device is capable of a Facetime call?

Is there a constant I can check to determine whether a device is capable of a Facetime call? I have a Facetime button in my app, but I only want to display it if the user is capable of making a Facetime call (i.e. user has iPhone 4 or iPad 2 right now, but want code to work for future 开发者_开发问答versions that come out).

Try using the canOpenUrl on facetime URL, as follows:

[[UIApplication sharedApplication] canOpenURL: [NSURL URLWithString: @"facetime://5555555555"]];