Not having money to hire a game developer may actually be a good thing for you.
Let me explain,
The probability that your game will be a success is low. The app marketplace is flooded with mobile games. The going rate for a simple 1 Level game is about $10,000.
Realizing these facts, how can you make your game idea a reality?
The answer is to test your game idea through a Proof-Of-Concept. There are some nice tools out there that allows you to create games without any coding knowledge. One of those tools is GameSalad.
Gamesalad enables you to develop a game in matter of weeks, release it on the app store and see if people like your idea.
If they do like your game idea, then you can hire a developer to add features not available in GameSalad. By this time, you already have a fan base and a good idea of its financial potential.
Remember, the most important aspect of a game is not the artwork or the features, it is the GAMEPLAY. If the gameplay is interesting and addicting, your game will be a success.