iphone application development - open to bidding

hello, i would like an iOS application developed for me. I'm not too good with coding, but i have a concrete idea which shouldn't be hard hard for a skilled person. what i would like, is an application that once is downloaded, u sign up (create account or login through Facebook/twitter) it will be a chat app similar to "tinder". the app will show the people who are currently using the app or have the app within 100-1000 meters (user has the option to refine). when the user goes in the app it will show who is on it in that radius. an example, would be, say you are in a library. and you see a "girl" you want to talk to. before talking to her in person, u hope she has the app. so u go in the app. it will show all the users who also have the app. u look through the users online and see if u can spot her. you can then have the option to "nudge" her or just straight up chat with the person. it can work in multiple capacities like this. I don't know if this will have to be through bluetooth or a wifi connection. can you develop this? if u have more questions or want more detail, plz reply. thanks!