NSTimer alternative that doesn't retain the target.
You can create a NSTimer with target and selector and the NSTimer will not maintain a strong reference to target:
+ (NSTimer *) scheduledTimerWithTimeInterval:(NSTimeInterval)interval
target:(id)aTarget
selector:(SEL)aSelector
userInfo:(id)userInfo
repeats:(BOOL)repeats;
Or you can use block to create a NSTimer:
+ (NSTimer *)scheduledTimerWithTimeInterval:(NSTimeInterval)interval
block:(HWTimerHandler)block
userInfo:(id)userInfo
repeats:(BOOL)repeats;
MIT