Mobile devices now have the unique Google Priority Inbox on Gmail. So when you open up Gmail on your mobile, you are greeted with the Priority Inbox. The Priority Inbox has been designed to clear the clutter in your inbox and filter out the less important e-mails. Although Google has introduced the Priority inbox in Gmail on PCs quite a long time ago, it is only now implemented on the mobile Gmail App. In an attempt to overcome e-mail overload, the system algorithmically selects and decides which mails the user is most likely to need to see on a priority basis.
The Priority Inbox shows filtered e-mail from the regular inbox in one of the three categories which are “Important and unread”, and “Starred” and “Everything”. This is a very interesting feature, leaving a clutter of inbox items for review later, barring the important mails, you want to see. The inbox receives all the mail and only those marked Priority appear in the Priority inbox, allowing you to attend to important mail promptly without having to search the full inbox.
This feature has been activated on all operating systems be it Android or iOS or others. All versions of phones supporting HTML5 have this feature available. Android 1.5 and above, iOS 3 and above support this without any feature required to be added. However, setting up of Priority inbox is not available on the mobile app directly as of now. You are expected to set it up on the main Gmail on your desktop application for it to appear on the mobile App.
Google has taken care to make these available in editions of their Standard Google Apps, Google Apps for Business, Google Apps for Government and their Google Apps for Education. In fact the app is available in over 44 supported languages. This is one more good introduction by Google for e-mails.