You would need to hire a programmer if you wish to pursue developing this software idea. There are several freelance sites like Odesk and Elance. I would use a Non-Compete or Non-Disclosure agreement before discussing with anybody if you care if your idea is "borrowed".
To find out if something already exists, just google different phrases describing your idea. If you know a precise technical term, you should use that. There may be more precise ways of finding out, but that's a start and it doesn't cost anything.