Apple and Google will not take part in the ESRB ratings system for games and apps in the US.
The Entertainment Software Ratings Board, usually associated with the console gaming business, wants all developers and publishers to submit details of in-game content, which will then be judged by the group and rated for age groups accordingly across all formats.
But both Google's Android and Apple's iOS services will continue to use their own ratings system, leaving the ESRB without the support of the two largest mobile formats.
"We've put a lot of effort into Android Market's rating system, which now works well globally," a spokesperson for Android told Digital Trends.
"While we support other systems, we think it's best for Android users and developers to stick with Android's existing ratings."