Data-saving Android app Opera Max has unveiled a new feature that enables mobile operators to offer users free access to select apps for a set period of time, in a move intended to let users in developing countries access a wider range of services.

The feature, called App Pass, is aimed at markets where many users might find mobile data to expensive, and is currently being tested in a number of Asian markets by Telenor Digital.

App Pass enables users to check out apps that they havent previously tried to see whether or it not they wish to change to a data plan that would grant unrestricted access to them.

The feature is similar to Opera Maxs Web Pass feature, which lets users browse pre-selected sites for free, with operators or sponsors footing the bill for the data. It also enables operators to deliver ads, offers and other marketing content to users as they complete the process for accessing apps for free.

“Were excited to partner once again with Telenor Digital to innovate in how mobile data is packaged and offered to consumers,” says Lars Boilesen, CEO of Opera. “App Pass build upon Operas achievements with Opera Web Pass and Sponsored Web Pass in making mobile data affordable and easy to use for end users. With App Pass, consumers can enjoy their favourite apps and try out new ones with just two clicks, using the Opera Max client already on their devices.”

“Were eager to see how this service is received in our markets,” said Rolv-Erik Spilling, head of Telenor Digital. “App Pass is designed to give customers easy control over costs related to data usage. The challenge of so-called bill shock is high on our agenda, and these kinds of initiatives from Opera play an important part in addressing the issue.”

While these zero-rating initiatives have been praised for enabling users who might not otherwise be able to afford online services to access them, they have also been criticised by net neutrality advocates who say they create a two-tier internet, where apps that have not partnered with operators are placed at a disadvantage, and much less likely to be used.