App for iphone and android - repost

I need a freelancer to develop an iphone (and depending on budget also for android) App. The application shoud perform the following tasks: 1. The user should be able to register a user name and password, along with some personal information 2. The app should have a Dot lock screen and when performing a sequence of dots(activation= (draws a specific line shape) it should send a message to other users of the app, as well as posting a message in the users twitter and facebook account. 3. The message should contain the current accurate location of the user, along with some predefined information. 4. The app should be capable of detecting the users located within a 5 km ratio. These are the main functions of the app. I´m looking for an experienced developer with the necessary capabilities for developing in a reasonably short time this app. Thanks!!