Crashes periodically

This is a set of mini games, daily group of tests and stat tracking for "brain training".
Is has a nice UI and fun characters (Albert Einstein and a cute little robot) but the game crashes. Im on an iPhone6 in Feb2016. I wont be purchasing the full version because of the bugs.

Scott Neufeld about Einstein™ Brain Trainer Free: 30 exercises to practice your logic, memory, calculation, and vision skills - more effective than sudoku, puzzle, or quiz games, v1.5