In their latest attack on Google Play and the Apple App Store, Amazon has done away with their free-app-a-day policy and has instead created a new app known as Amazon Underground where they claim to be giving away over $10,000 worth of free apps and in-app purchases.

The way Amazon has pulled this together is by making a deal with many app publishers in which, instead of making money off of sales and in-app purchases, the publishers and developers will now be earning revenue based on how long players play the title.

“We’re paying them [developers] a certain amount on a per-minute played basis in exchange for them waiving their normal in-app fees. To be clear, we’re the ones picking up those per minute charges so for you it’s simply free. Just look for apps and games marked with an ‘Actually Free’ banner.” Amazon took to their website to explain. According to a document found on Amazon’s page, they will be paying $0.0020 in the United States for every minute a user uses a developer’s app.

So far, many well known developers have contributed to this project, including Rovio, Disney, Gameloft, Sega of America, and Halfbrick Studios. Just some of the more well known apps currently offered under the ‘Actually Free’ banner include:

• Goat Simulator
• Angry Birds titles (Space, Rio, Stella, and Bad Piggies)
• Cut The Rope titles (Cut The Rope, Cut The Rope 2, and Cut The Rope: Time Travel)
• Threes
• Fruit Ninja
• Disney’s Free Fall series
• Disney’s Where’s My Water? series (including spin-offs Where’s My Mickey? and Where’s My Perry?)
• Jetpack Joyride
• OfficeSuite Professional 8
• Magicka
• Ellen’s Heads Up!
• Sonic CD
• PAC-MAN Friends
• Farming Simulator 14

The biggest complaint going around is that these app require invasive permissions, but that can be explained by the way Amazon is paying the developers.

“The Amazon Underground app is a long-term program rather than a one-off promotion. Over time, we’ll continue to invent and add more benefits to Underground. For now, enjoy some actually free apps and games!” Amazon stated in a letter to customers.

If you are an app developer and are interested in Amazon Underground, make sure to check out this video created by Amazon!