Need an app developer/programmer

Hi, My name is Mohamed, I'm 18, and I study Business Administration at ESSEC Business School in Paris. I need a programmer in order to create an app that I've been thinking about for almost a year now but couldn't find a place to hire programmers. Fortunately I came across this site. Well, the concept of the app is quite simple. It's based on the concept of service rental. People can paye others to do services for them, tasks, loan things and do a lot of other things amongst that. But the app, in the way I've thought it , has to be based more on demande rather than offer, people post what they need and another user can see the needs of people around him in map and if he finds a demand that he can respond to then he will be able to accept the demande and after doing the service or loan the demander can then confirm the service is done via the app and the user that did the service gets then paid also the app the amount pre-established by the demander. The financial aspects and the economic model are a bit long and complex I'd like to talk them on the phone or somewhere else. Looking forward to working with you, Mohamed.