News websites often have loads of content loading on each page. So when you click on a link to read a news article (perhaps this one), it can sometimes take quite some time for the page to load up. Especially if you are on a slower connection. That is why Google brought in AMP (Accelerated Mobile Pages). It essentially strips down the site, giving you just the content you are looking to read (of course the site branding like the logo is still in tact). These AMP links have been available in Google searches and other places around the web - including the Google+ mobile website - but now they are finally supported in the Google+ app on Android.
What that means for users is that if you click on a link from the Google+ app on your Android device (it's not yet available for the iOS version of the app), and it is an AMP link, you'll be taken to the AMP version of that page, instead of the normal, slower version. The Google+ app will also show you which links are AMP links, before you even click on them. In the picture preview that appears above the link, you'll see the AMP logo (which is basically just a lightning bolt) next to the website's main URL (something like "google.com"). So you'll know that it is an AMP page before you even tap on the link to read the webpage.
Support for AMP is available in a new version of the Google+ app, which is available on the Google Play Store today. The app is version 9.2, and you can also download it from the link down below. It is in a staged rollout, so you may not see it on your device for a few more days. But if you want the updated app right away, instead of waiting for Google to push it to your device, feel free to sideload the APK below. You'll just need to make sure that "Unknown Sources" is enabled, this is done by going into Settings and tapping on Security and you'll see the option there.