Observation Zen is one of Brain Zen series focus to train brain core abilities.This app contains the following games:
1. Find Difference: Find the different 1 out of 4, the color sequence is the key.
2.Category It: Slide middle thing to right category, character, number, stuff or color dot. You have to reaction quickly.
3.Same or different: Judge the stuff same as previous or not.
4.Red vs Blue: Tap red or blue
You can also change the theme and difficulties as you like.