427816 Android App Req - Linked to website

Hi, Im looking at developing a website that would require intergration with an android app. The app would be similar to grindr on the iPhone. Members sign up at the website and create a profile. Member downloads app onto their phone and logs in using membership details from website. GPS tracking plots member on map and also lists everyone else who is using the app. Member can see members nearby and can click on their icon on the map to view their details (profile) that was created on the website. Member can then send other person a message and the other person can read it and reply. If you have any questions, please feel free to ask. The software for the actual website as yet has not been decided. Previous experience developing for android would be prefered and examples shown.