The UUD gives Madvertise the ability to offer advertisers campaigns in which it can track Click Through Rates (CTR), download and conversion tracking, target specific audiences by criteria such as location, as well as offer other "sophisticated" methods of behavioral targeting.

"Data collection, analysis, and enrichment on mobile is rapidly changing. The days of cookies as a valid identification metric are over and any company still relying primarily on them as a basis for their technologies will be rapidly left behind," said Adam Drake, the Vice President of Research and Chief Data Scientist at Madvertise.

Meanwhile, Adfonic has been putting its weight behind ODIN, or the . Despite using part of a devices' MAC address to generating reusable device identifiers, its backers insist that it is an anonymous and secure technique.

"While we share the concerns of others in the industry about the long term viability of the MAC address as a tracking solution - it shares many of the same privacy issues as UDID - this alternative has some immediate traction with developers and exchanges, and is easily implementable for a variety of use cases. Adfonic will be supporting ODIN-1 for both publishers and advertisers, and working with the ODIN group on the evolution of the standard," said Biggs.

Another solution that Adfonic comes as part of its with the developers of AD-X tracking technology to come up with what is "not specifically a UDID replacement" but does provide "a way for campaigns to be tracked across both mobile web and in-app inventory".