What is the name of the Android app store before it was renamed to Google Play?

Before it was renamed Google Play, Android's app store was called Android Market.

Google announced Android Market in August 2008 and made it available to users on October 22 of that year. It was the original distribution channel for downloading applications to Android phones, including the HTC Dream, the first commercially released Android smartphone. The service gave developers a place to publish software and gave users a central catalog for discovering and installing apps.

Android Market originally focused on applications, but Google's digital-content strategy expanded during the following years. Google launched an online interface in 2011, added features such as app rankings and content filtering, and introduced additional digital storefronts for books, music, and movies.

In March 2012, Google rebranded Android Market as Google Play. The new Google Play brand brought Android Market together with Google Music, Google Books, and Google Movies under one umbrella. “Play Market” is a common informal variation in some regions, but it was not the original official name. Google Play Store is the later name associated specifically with the app storefront.