Moving an important contact to Favorites in your Android app
To do this on your Android app, follow the instructions below:
Select Favorites as shown below and click on add + sign.
Select Heart icon to add contact into favorites list.
Moving a Messages to Starred Folder
To move message into starred folder select more action from top right corner and select star.
You can also change the left/right swipe action to 'Star' and swipe left/right respectively to star an email.