A great app of you want your kid to train and automate calculations, and math, with fun. The free version gives an excellent idea of how the game works, but remove it and buy a full version (at this moment 4,49) if you want to use it as a family: I did not and paid one time extra. But given the excellent quality of the app I don’t mind. The levels the paid version unlocks are challenging for parents as well because of the time pressure...I reckon it is a great brain-trainer for adults as well for that reason. And: you pay once and that’s it, no ugly subscription.
I wish everybody as much pleasure with this app as our family is having! Thanks developers!