Back on September 9th of this year, Amazon released a big update to its main Android app, which lets you purchase things from your phone. That update added the ability to stream Prime Instant Video content on Android smartphones, albeit with a rather clunky set up process. Amazon was very vocal in touting the new Prime Instant Video features in its press release announcing them, but it didn't mention the fact that you can now download and install Android apps directly from Amazon's main app — no install of the separate Amazon Appstore needed.

That little feature has flown under the radar for about six weeks or so, until TechCrunch discovered it earlier today. The current Amazon Android app has a section for Apps & Games from which you can just buy and install any Android app Amazon offers. You still need to enable the "unknown sources" setting in Android's security settings to complete installation of the app, but the process is still far less onerous than having to install Amazon's Appstore, which is not available through Google Play.

Amazon is offering an app store that competes with Google, yet can be downloaded from Google's own Play Store

As TechCrunch notes, Amazon is essentially offering an app store that competes directly with Google's own Play Store and can be downloaded from the Play Store itself. Amazon isn't the first developer to do this — a quick search for "app store" in the Google Play Store brings up carrier-branded stores and other, lesser known options — but it is most certainly the most prominent one.

Amazon is using the integration of its digital app store into its main app to recommend apps and products based on your purchase history of physical goods, something it never did in the standalone Appstore. The Amazon app is listed as having 50 to 100 million downloads from the Google Play Store, so in addition to the deeper recommendations, Amazon is greatly expanding its ability to reach Android users looking for apps. With the ability to purchase and download apps directly from Amazon's main app, there's little to no reason for anyone to sideload Amazon's Appstore and it will be interesting to see if Amazon decides to continue offering it to its customers or preloading it on smartphones from Verizon Wireless.