In case you missed it, the Google+ app for Android got updated recently to version 7.1.
The update is mostly comprised of bug fixes - 37 bug fixes to be exact - but it also offers fixes for 17 "accessibility issues," a fix for the "keep contacts up to date" setting, and one pretty handy feature that makes the bottom tab bar just a little more useful.
As shown in Luke Wroblewski's illustration above, tapping on the home icon in the bottom tab bar will instantly scroll you up to the top of your home stream, a useful interaction found in other apps with bottom-mounted navigation like Instagram.
It's a small touch, but if - like me - you often find yourself deep into the stream hoping for help from the "new posts" toast, it provides a better solution.
Just in case you don't have the latest version yet, you can find it on APK Mirror here.
Source: Luke Wroblewski (Google+)