3/5 rating based on 54 reviews. Read all reviews for Brain Tuner X for iPhone.
Brain Tuner X is free iOS app published by GreenGar Studios
Salomon1931
A nice exercise to get the grey matter activated. The problems are very simple but do require concentration and quick thinking to get them right. I didn't give it five stars because in order to truly tune your brain they should provide problems that challenge you on some other dimension beyond simple arithmetic with a time constraint.
Jurmum
Fun way to kill time & still feel like you're doing something productive