Ok - so a few things I noticed:
I like the design, at least on the screenshots. Flat design, minimalistic, that's nice!
Downloaded the app to a Galaxy Tab 8.4 an the icons seem to be unsharp and pixelated.
The bright shade on the icons right side look weird when they appear in the main menu - maybe my eyes are playing a trick to me there...
In addition, you might want to rework the text fields. "The man who passed the test: Speak lies"- doesn't sound well written.
Finally - what is the point of having 4 different tests that all do the same ? Try to get some variation - maybe Q&A, random numbers, truth or dare style stuff...