Three Buttons By Guo Bo

Three Buttons comes from Guo Bo.  It's similar to 100 Floors which came out a few years ago.

The objective is to light up each button at the same time.  There are 49 levels and each one is completely different.

I solved levels 7, 8 & 9 with mostly guessing. 
https://itunes.apple.com/us/app/three-buttons/id1078188629?l=zh&ls=1&mt=8
http://guoboism.com//games/threeButtons/