Amazon launched a new Android app with “all the functionality of our regular Amazon mobile shopping app, plus an exciting addition: over ten thousand dollars in apps, games and in-app items that are actually free”.

It has achieved this by working out a new business model with app and game developers: “we’re paying them a certain amount on a per-minute played basis in exchange for them waiving their normal in-app fees,” it said in a note on its website

“To be clear, we’re the ones picking up those per minute charges so for users its simply free. Just look for apps and games marked with an ‘Actually Free’ banner,” it added.

The key benefit for developers is that all Android app users will generate revenue for them, meaning “it’s a win for both customers and developers”.

“There is no more guesswork around getting in-app purchases optimised for the 2 per cent – 10 per cent of customers that reportedly buy them. You can now focus on creating great content, storylines and characters that keep customers coming back,” it said.

The company was also keen to point out that Amazon Underground is a long-term programme and not a one-off promotion. “Over time we’ll continue to invest and add more benefits to Underground,” it said.

It did not reveal how (or if) it will generate revenue from the new venture.

Explaining why it emphasises “actually” free, Amazon said many apps marked free use in-app payments to charge users for special items or to unlock features or levels. Such ‘freemium’ apps have come under scrutiny.

In July last year, the FTC sued Amazon for policies in its app store that saw children reportedly spend “millions of dollars” on in-app purchases without parental permission.

Underground will not be available via Google Play because “Google’s rules don’t allow an app that offers apps or games”. Instead, users can download it from Amazon.com.

For users of Amazon’s Fire HD and Fire HDX tablets, the apps will be automatically available.