App Stores helps you discover all the major sources for Android apps, as well as some of the more obscure ones. But rather than directly enabling you to download apps from those stores, it requires that you install each store's app, so that it ends up being nothing more than a list of shops with useful links. Still, for app lovers it's a handy tool, one that can help you discover thousands of interesting apps that are not available on Google Play.
You won't find App Stores in the Google Play Store, so you have to grab it from Download.com and install it manually using a file manager. The app comes with a straightforward interface that lists app stores, dividing them into 51 verified stores and 15 unverified stores that may contain spyware; if you click on any of them, the app takes you to that store's Web site. The app gets a thumbs up for providing a download button for every store's app, though at times you can encounter a broken link. You'll also like the app store's convenient search feature. Otherwise there are no settings to configure, and the zooming in or out feature seems redundant.
If you like to download apps from sources other than Google Play, App Stores can make it easier for you to do that, as well as to discover lesser-known stores based in China or other countries. But keep in mind that using it can expose you to security risks.