Did you know that Mozilla has an app store? It’s called the Firefox Marketplace, and it’s an area where developers can sell HTML5 apps. It’s going to be a central part of the Firefox OS coming to smartphones early next year. Developers wanting to get a head start can now start gathering important feedback from early testers.

Mozilla announced today that the Firefox Marketplace is now available to Firefox Aurora for Android users. It’s encouraged that early adopter and testers try out the new marketplace before it goes live anywhere else. Developers will need to be at the top of their game for the full release on Firefox OS in early 2013. This allows them to gather all too important feedback before then.

In the first iteration of Firefox Marketplace, Mozilla says that there are apps available in following categories – games, productivity, and news & media. Some of the apps that users can access starting today include Twitter and SoundCloud.

It should be noted that the Firefox Marketplace is a little barebones at the moment. The app page only features a single screenshot, a description and a place for users to write reviews. As Mozilla promised back in May, the privacy policy for each app is plainly visible.

Those who want to try out the Firefox Marketplace will have to download Firefox Aurora. It’s not available on Google Play so you’ll have to download it from the Web site. As such, you’ll also need to allow your phone to install apps from unknown sources.

For developers who want to start building Firefox Marketplace apps, Firefox has some great resources available to you. Check it out here.