Apple reportedly mulling tracking tool for app developers

Only days before Apple's big developer shindig gets underway, the ship of state is leaking one rumor after the next.

The latest, courtesy of The Wall Street Journal, has to do with Apple coming up with a new way for its mobile app developers to "track who uses their software."

The new tool, which could be detailed in the coming weeks, aims to better protect user privacy than existing approaches, these people said. It comes after Apple last summer rattled the mobile industry by saying it would stop allowing app makers to use a unique identifier embedded in iPhones and iPads to track users across different apps. So far, the company hasn't aggressively enforced that policy.

The article does not offer any specifics on how the technology might work.

Apple said it would begin phasing out unique device identifiers, or UDIDs, as part of iOS 5, which was released last year.

Those are the identification codes, akin to serial numbers, that are associated with the device (even if it has multiple users), which had commonly been used by analytics and third-party advertising networks -- and by developers who want to allow users to set preferences that will persist the next time an app is used. Developers are now being encouraged to create their own unique identifiers, specific to an application, but Apple has given little public guidance.

Then, in March, developers began to report that apps that continue to use UDIDs are being rejected by Apple's App Store approval process.

The unique numbers were useful to advertisers, who could track a user's behavior across multiple applications, something Apple did not offer.

However the move also got Apple in trouble. In several lawsuits lodged against Apple seeking class action status, lawyers referred to the UDID as a "supercookie" and complained that Apple does not provide users any way to delete or restrict access to their devices' UDIDs.