Like and iphone Assistive Touch (仿作苹果手机Assistive Touch的一部分效果)

#Why?

1. 配合Android手机沉浸式隐藏虚拟按键后快捷操作 (Nexus5屏幕变大了)
2. Home按坏了怎么办?找我就对了

#V1.0

1. Click it to return desktop (点击返回桌面,跟Home效果一样)
2. Two seconds later fades (2秒后变淡)
3. Run about (跟着手势移动)