Amazon has their own platform for apps and gaming. While not as robust as Google Play and the App Store, they have a decent selection. To better compete on the gaming front and offer a better experience to users, Amazon announced a new feature called GameCircle which allows users to record and track achievements as well as save their game right to the cloud.
GameCircle is currently available for the Kindle Fire thanks to APIs being available to developers. While some may wonder why developers would want to invest time with the Kindle Fire, there are quite a few in use and currently has a little over 10% market share. The new feature is only available to apps that are exclusively available on the Kindle Fire and not through Amazon's app store.
Maybe this will change as their app store works on more than just their tablet, but also any and all Android devices. GameCircle has three main features and the first one is achievements which allow players to get badges, awards, that kind of thing. The second feature is leaderboards which don't really need an explanation. Lastly, and a rather cool feature is the ability to sync game progress.
For example: Say you delete an app or switch to a different phone. Instead of being out of luck, once you install the app again, you'll be able to start where you left off. Here's a video below that talks about GameCircle...