Question

How do I detect when an iOS app is launched for the first time?

Answer 1

Pretty much what Marc and Chris said, though I prefer to change the value when the app quits in case there’re multiple areas of the application that need to know about it. In code:

Objective-C

// -applicationDidFinishLaunching: [[NSUserDefaults standardUserDefaults] registerDefaults:[NSDictionary dictionaryWithObjectsAndKeys:[NSNumber numberWithBool:YES],@'firstLaunch',nil]]; // to check it: [[NSUserDefaults standardUserDefaults] boolForKey:@'firstLaunch']; // -applicationWillTerminate: [[NSUserDefaults standardUserDefaults] setBool:NO forKey:@'firstLaunch']; 

Swift 5.0

// -applicationDidFinishLaunching: UserDefaults.standard.register(defaults: ['firstLaunch':true]) // to check it: UserDefaults.standard.bool(forKey: 'firstLaunch') // -applicationWillTerminate: UserDefaults.standard.set(false, forKey: 'firstLaunch')