Cloud based Platform for Building Mobile Apps

Need someone who can develop a platform for building mobile apps, similar to the ones in the following links: [login to view URL] [login to view URL] [login to view URL] [login to view URL] The platform should be extremely user friendly and develop apps for Apple, Android, Balckberry, Windows and HTML5. Users will drag & drop items in order to build the app they want. The should be a section with pre built templates. The idea is to take the best features of the examples above and develop a better platform. This task is not for amateur elancers. Send proposals and examples of previous work. Thanks