It's fine if you focus your app on highly motivated language learners, or people bothered by gamification. The issue is going to be how to market to those peopl

It's fine if you focus your app on highly motivated language learners, or people bothered by gamification. The issue is going to be how to market to those people. They need to hear of your product somehow. Having an app oriented toward being used by anyone has the advantage that you can slap an ad up anywhere, and you'll reach a potential customer.