[idoh]

I have a lot of experience with outsourced development, my last couple projects have been like that and it has worked out really well (as in, profitable apps with a lot of users). So I know it's possible.

For concern about rights / stolen ideas, I don't think it should be a major problem. By and large they are interested in getting paid, if you are a good partner then things should be OK. There are things you can do to mitigate the risk, e.g. if it is an iOS app then you submit the app yourself and get the payments directly, make sure to get the source code, etc.

If you want to know more then let me know.