Intellectual property rights

It sounds like you may be voicing two concerns. One concern would be getting ripped off by the development company. The second concern would be having the idea copied by others in the industry. If the app is novel, you can file a provisional patent application to protect it before the app is created and without having the programming background to build it on your own. All you need is a clear, distinct vision of how it will operate and what the novelty is. If patenting is not an option, it comes down to contracts, trademarks and copyrights. You can execute a contract with the development company to make sure they don't build anything similar to your idea. You can then copyright the appearance of some of the app screens to keep others from blatantly copying the software and you could copyright the app code. You trademark the materials on the app that differentiate you from the competition. If patenting isn't an option, there is always going to be room for someone to create something comparable without violating your contracts/copyrights, but then you hope being first to market gives you an advantage over copycats. I believe much of Angry Birds could be imitated (at least, I'm not aware of any patents), but nothing comparable has been created that has provided the same success. They were first to market, they built a brand, and they keep producing new material and that has given them a leg up. And that IP is easy to sell. Good luck.