Contact a lawyer. I'm not one, but there are laws that protect you (probably... Do you have any trademarks, patents?). Also, You have intellectual property righ

Contact a lawyer. I'm not one, but there are laws that protect you (probably... Do you have any trademarks, patents?). Also, You have intellectual property rights to your app regardless of patents or trademarks. If its a blatant copy, you probably have means for suing them and getting some $$ back. Again, not a lawyer, I could have said something completely wrong, but as far as I know what I said above correct.