Google is this close to bringing third-party app stores to the Play Store

Ahead of the wider release, Google is already testing a new option to enable third-party app stores on the Google ...
Tech Times on MSN

Google Play now hosts rival Android stores, but still controls every download

Google Play Catalog Access Program launched July 22 as the first court-ordered app store interoperability mandate in U.S.

Google Will Allow Third-Party App Stores On Android Next Week

Third-party app stores are coming to Android on July 22.
XDA Developers on MSN

4 Android app stores I always use instead of the Google Play Store

See beyond the Play Store.