Use NSUserDefaults to persist data between app runs
On the iPhone you generally want your application to start looking like it did when it was last run to give the user the impression your app is ready to pick up where it left off. NSUserDefaults provides an easy way to store your application’s settings between runs. Simply create an instance of NSUserDefaults and give it the key/value pairs you want it to save.
Storing an integer
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
[prefs setInteger: myIntValue forKey: @"intValueKey"];
[prefs synchronize]; // writes modifications to disk
Reading it back in
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
int myIntValue = [prefs integerForKey: @"intValueKey"];
or more simply
int myIntValue = [[NSUserDefaults standardUserDefaults] integerForKey: … Continue Reading