Hello friend, I think it's an excellent idea and even more so, all the effort you've taken to this point and to reach that point you have to take a little risk.

Do not be afraid of having your ideas stolen since there are thousands of applications and some similar ones, but where the best ones come out, so to speak, is the innovation of your application and at the same time ask for suggestions so that your application will continue to grow.

In order for your application to be successful you must first have something that catches your attention so that everyone starts downloading it and of course your rewards, my opinion on the rewards that you should also add gift cards and remember that your business will be a passive income with profits to long term.

Many luck in this project and that your application is a success.