Mozilla has announced that they are now accepting web apps for their upcoming Mozilla Marketplace.
Mozilla spoke about this new platform:
Today, we are incredibly proud to announce that the Mozilla Marketplace will open for developer submissions next week during Mobile World Congress. If you are an app developer interested in distributing and monetizing your app across device and platform silos, you should submit your app to the Mozilla Marketplace. Submitting your app will reserve your app name and give your app the chance to be featured in the launch later this year.
Mozilla Marketplace would become a prime challenger to Chrome Web Store which also feature web apps but is restricted to Google Chrome browser.