I have an idea for social networking app similar to those third party Twitter apps. It's for a specific group of people so I won't be doing it to make money off it. Since I won't be able to write it myself, I'd have to hire someone else to write it for me. I have written out a detailed blueprint on how the app should look and how the engine should work, etc. So, to make the question simple, say, if I hire someone to make an app just like Tweetie (meaning high quality), what should I expect in terms of cost and time?