- (void) applicationDidFinishLaunching: {
NSTimer *_timer = [[NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(onTimer) userInfo:nil repeats:YES] retain];
}
// call function when time is up (in this exemple :1 second. to change it, change scheduledTimerWithTimeInterval: 1 to value in second)
- (void)onTimer
{
// schedule code..
}