Have been an ardent and avid user of this app for a long time. In fact I would rate it as the best for online blitz chess with worldwide challenges from best minds... But I wouldn't rate this app any higher than 2 stars coz of the number of time cheating issues I have encountered using this app. I have lost so many close games where I had enough time to easily finish the game only to be cheated by time control by opponents which I'm not really sure whether this app condones doing!!!