Google has released the v4.5 update for the Gmail app for Android, whichbrings with it some UI changes, some of which are in tune with the recent changes seen on Gmail website.
The first thing you’ll notice is that Google has done away with the bottom bar that hosted buttons fornew mail, search, labels, refresh and menu. Three of those have now been moved to the action bar on topand refresh has been included in theUI in the form of pull to refresh. The options in the drop down menu on top to move between your accounts, folders and labels has now been moved into a drawer on the left.
You will also notice that Gmail now shows contact images for your mails. If a mail has multiple contacts, it shows them in a grid similar to the Hangouts app. If there is no contact image, it just shows the first letter of the senderin a colored background, which does look a bit silly. You can disable sender images for the mails if you wish from the settings.
v4.5 also includes the four new inbox options. You can have your mail sorted by Primary, Social, Promotions and Updates as you can on Gmail web, which makes it easy tokeep track of your mail.
Gmail 4.5 is now rolling out slowly toAndroid users worldwide. You can wait for it to be made available in your regions or you can download and install the APK from the link below.

http://www.androidpolice.com/2013/06/03/download-new-gmail-for-android-4-5-with-slide-out-navigation-and-brand-new-inbox/