Go4itest such have an amazing quality in both interface and arranging pattern of question as according to the users age. yesterday i played it with my nephew and niece which are only 9 years old so that iq test was as kind of their age when they were playing it and when i started to play it the question quality became more harder. So i like this stuff arrangement very much. I decided to play it everyday whenever i`ll have free time. Good work.