### Icon
[X] add doc
[ ] add example

### Button
[X] add doc
[X] add example

### [ ] BarButtonItem

### NavigationBar
[X] add doc
[ ] add example
[ ] add Back BarButtonItem

### TabBar
[X] add doc
[ ] add example

### PushNotification
[ ] add doc
[ ] add example

### Chat
[ ] add doc
[ ] add example