I didn't read through all 84 responses, but I just wanted to suggest something that's probably been suggested ... any thoughts to add a sort of graph with more in-depth "stats" to the app? Sort of like the Loggr app? I was going to use that app instead but it's way too busy, so I chose Pinscores, but I did like the depth it had.
For example, playing a machine ~10 times and seeing how your scores have improved or gotten worse, your mean score, standard deviations, etc.