OpenKit has signed up more than 500 developers since it was announced late last year, and is now moving to an “official private beta programme”.

Described as “the first completely open backend-as-a-service (BaaS) platform for mobile developers with a guarantee of no lock-in of developer data”, it is designed to enable features such as cloud data storage for game state, leaderboard, achievements, multiplayer features, push notifications and in-app purchases.

Unlike rival services such as OpenFeint, OpenKit is not designed to be a user network: developers can take user data and the OpenKit source code and host their own backend service.

The platform will also provide a universal authorisation service for any user network, including Facebook, Game Center, Twitter, Google+, Gree, and so on.

OpenKit was created by Peter Relan, a co-founder of OpenFeint, as a response to the closure of the service by Gree, and to reflect a “broader need in the industry” for an open-architecture to deliver backend services, without lock-in.

“On December 13, we announced the OpenKit project to solve the recurring problem in 2012 of developer furor over APIs. Hundreds of developers signed up immediately to tell us what they wanted,” Relan said.

Other features include a single API and service across iOS and Android.