类似win8开机界面的进度展示效果。有5个白色圆点在循环转动，可以设置圆点的颜色。效果非常棒。-Similar win8 boot interface showing the effect of the progress. There are five white dots in the loop rotation, you can set the color dots. The effect is great.

主要实现app开机动画（两种模式），对初学者较为有利-startup animation for iOS app