The version I used was beta 1.2.20.1 also my phone is Android Motorola Moto Z Force

To get the bug create a new world and go to resource packs and add one to the world. After that click the ! Button under the resource pack
After that you will get a screen of static and if you click the back button on your phone enough times you will be on the main menu where if you spin your skin it looks weird and made of triangles and if you hover over the buttons the screen changes and if you click the back button it will change as well.
*The resource pack I clicked the button on was Custom UI
I also added Mine-Tornado Textures witch did not have a ! Button
I also have the Mine-Tornado Add-On