Kivy Links

https://www.youtube.com/watch?v=G6Z_O0mlIh0&list=PL1Sfe0mki1OXSLb7JTXeZBkzCyfotOxPz&index=1
https://www.youtube.com/watch?v=4gH8oB-GwA8
https://www.youtube.com/watch?v=CYNWK2GpwgA&list=PLQVvvaa0QuDe_l6XiJ40yGTEqIKugAdTy
https://kivy.org/docs/api-kivy.uix.button.html#kivy.uix.button.Button..