Create a database driven mobile application for IOS and Android

The project requirement is to design an application that works on both iOS and Android platforms. the following is a very basic description of the application: The app is a social interaction app that in theory should gather information about people who download it form their Facebook/instagram account, stores it in a database on a server, runs algorithms that lets the users interact and message each other based on certain criteria in the info. The app will have a very simple interface and most of the work is in the back end database programming and the requests sent and received from the app. The app's main idea is settled but there are still some details to be agreed upon with the developer and possibly some changes so that is why i want to work on an hourly rate. also, i am looking for someone with previous experience in both app development and database programming. and i need to see examples to back up the experience. In addition, this is a post for the programming aspect for the app i am planing to hire a professional designer for the graphics.