iPhone / iOS: Detect if user has run this version before

hasRunThisVersion.mm

// Warn if this is the first run of this new version
NSDictionary* infoDict = [[NSBundle mainBundle] infoDictionary];
NSString* version = [infoDict objectForKey:@"CFBundleVersion"];
NSString* defaultsKey = [NSString stringWithFormat:@"hasRunVersion%@", version];
BOOL hasRunThisVersion = [[NSUserDefaults standardUserDefaults] boolForKey:defaultsKey];
Log(@"hasRunThisVersion is %d", hasRunThisVersion);

if (!hasRunThisVersion) {
    // Do things you want to happen only once

    // Well, they've run it now
    [[NSUserDefaults standardUserDefaults] setBool:YES forKey:defaultsKey];
    [[NSUserDefaults standardUserDefaults] synchronize];
}