Write an iPhone application

I am looking to have an app developed for iphone and android (cross platform compatibility). The app will be a messenger app, similar to an app called Firechat. Basically, the app gives users the capabilities of being able to contact one another by Bluetooth only. If I have no internet connection or phone service, I can use the app to send messages to individuals around me by bluetooth and Wifi (Wifi is turned on to work, but mainly the phones are using bluetooth to communicate). For example, if I am on an airplane in the back (you can make believe I am person number 1) and you are in the front (you can make believe you are person 20), I am able to send you a message through the app with bluetooth. Even though you are too far away, the message will travel through numbers 2 through 19, using them as an intermediate to deliver the message to number 20 (without allowing numbers 2 through 19 to view it because it is being sent private). This is the main functionality of the app. Messages need to be able to travel privately to another party without being viewed by others. I also would like small chat room functionality as well, as in the ability to make a group between users who want to contact each other. The profile and sign up process can be extremely simple. The profile just needs a picture, name, and username. Sign up can just be email address with verification or phone number verification. It will also have the ability to add users as friends to make it easier to send messages with each other. The app will have in-app purchases to allow the users to be able to use the app. Here is a link to their video explaining how it works: [login to view URL] I do know iOS uses Multipeer Connectivity for it to work. I am not sure what it is called for android or for it to work cross platform. I want an app very similar, but ultimately it will have a different layout.