For what is is, this is a nice little app. The interface is simple and clean. Almost too simple— you might not be quite sure what to do, but you touch on a move and then it shows all of the different responses and the percentage played.
So you can just see what is most common from the 2,000,000 games — but WHAT 2,00,000? I wish we knew that — the computer has crunched.
If it is so good and interesting why the 4star? Well, too little support. One of the lines has Rook a1-e1. Other than their being a knight and queen in the way, it is a good move. How to correct this error? Give feedback? Don’t know.
In addition the testing doesn’t seem to work. I made the right play but the computer still thought me wrong.
Still I like the app. I love the numbers, I love the way you can go forward and backwards checking out possible moves along the way.
It is a good app and if you like chess you should try it.