If you thought Android needed another app store, today's your lucky day: Mozilla's latest Firefox beta for Android includes access to the Firefox Marketplace, a new app store through which users can find and install HTML5 applications on their Android phones. The store is similar to the Chrome Web Store, which also sells Web apps, but is currently available only for desktop operating systems.

Accessing the app store requires you to download Mozilla's latest Aurora build of Firefox to a supported phone or tablet. Since it isn't available through Google Play, Firefox's page briefly walks you through the process of greenlighting apps from third-party sources, and then downloading and installing the application on your device.

There aren't many applications in the Marketplace at present, but the ones that exist are currently free. On my Nexus 7, the performance of applications that are also available natively (like Twitter) seems roughly comparable to the native versions, and the apps' operating system integration is pretty impressive—icons show up on the home screen among your standard apps, and they also show up in the app switcher (though with a generic name and icon rather than their own).

The biggest downside for now is that, like applications in Google Play itself, many of the Mozilla apps appear to be optimized for a smartphone screen rather than a tablet's. Paid apps and in-app payments are also currently disabled, though a notice from Mozilla indicates that "they will be available again in October 2012."

Like all new Firefox features, the Firefox Marketplace should become available in the beta and stable branches of the browser as development continues. The Firefox Marketplace will also be a major component of Mozilla's Firefox OS when it officially launches next year.