What I want to create is a mobile app, nothing fancy, and see if I can sell the mobile app. Because it's such a simple idea, that's where my fear comes from.
If it is a simple idea, and is making money, it will be copied. There's a notion in business called "barriers to entry", and it sounds like you are entering a niche where there are none. You should get comfortable with this notion; it's not the outsourced developer you have to fear.