5 stars: Very clean app, and it really is an app, not a game. The app consists of 30 pretty simple exercises to test your reaction speed, and that's it. The app does have some problems, sometimes the exercises have weird glitches and it seems as though there is a weird interaction with penalty time and your average. I'm giving it 5 stars though, because for such a well-designed app there are no full screen ads! Great app, recommended.
4 stars: Great aim trainer and reaction training. But maybe for levels like level 6, in your records, you can also see what mode you chose(Complication mode on or off, and 3x3 or 4x4 grid). It would be nice to see those since the reason for having records is because you don't remember your records, thus it would be incredibly handy to be able to check those too. Overall, excellent game, entertaining and great for the market it's trying to target.
4 stars: Fun app. Reaction speed is the most important skill to have in my field of work. But uh... It's kind of hard to complete the color-based levels quickly with severe colorblindness. This wouldn't be so bad, but you can't progress without clearing the level in average or less time without paying, which I can't really do. I'll probably pay the $2 anyways, but otherwise it's a neat little app that I think probably does help with reaction speed.
3 stars: Its an okay concept. You get five tries to get average or above consistently in one thing. Repetitive in that manner- which i must say, ...