sand:box

The amazing physics game a game with materials to build something cool would recommend

Very satisfying and stress relieving but after you've tried every thing you get bored

There is such a game "Sandbox" in Google Play .... so, this is it only at maximum! Here you can literally build a nuclear reactor (a bomb too), the only negative is the interface, which is too small and incomprehensible, but you can figure it out :)  I will ads"Sandbox" myself for comparison. (according to the Powder Toy script, a rather old thing but cool and updated)