I just got this app at my kids tournament and started tracking the match stats in his second match. I have to say that this app is pretty easy to use. I actually didnt have use the undo function but I could see the need for it (I wonder though how useful it is to allow to undo up to 3 previous points, I have a hard time remembering the previous 2 points). I do love the graphs and also the ability to know the placement of serves that worked for my son. Being able to track return winners also tells me how aggressive the returner is or how effective the second serve is. This app tells me a lot about what he needs to work on and it costs a fraction of one private tennis lesson.
TennisParent about Tennis Trakker Pro