Apple and Google have refused to take part in an app-rating system.
The CTIA, a wireless industry group and the Entertainment Software Rating Board have launched a platform which allows app developers to rate their applications to let users know the kind of content the apps offer.
The information is translated into age ratings by the ESRB which are then conveyed to consumers when they go to purchase the app.
Wireless carriers AT&T, Sprint, T-Mobile USA, U.S. Cellular, and Verizon Wireless are taking part in the voluntary program while Microsoft and Research in Motion have confirmed their participation among mobile apps and hardware makers, as reportedby Tuaw.
"We've put a lot of effort into Android Market's rating system, which now works well globally. While we support other systems, we think it's best for Android users and developers to stick with Android's existing ratings," said Christopher Katsaros, a Google spokesperson, in a statement.
Meanwhile, Apple, which is known for its no-porn policy, already applies a series of strict app content and functionality checks which makes the new content rating system virtually useless for its developers.