There actually is a way to avoid piracy of iOS apps: build an app that requires server-side computation/algorithms of some sort and combine that with the signed

There actually is a way to avoid piracy of iOS apps: build an app that requires server-side computation/algorithms of some sort and combine that with the signed receipt capability of in-app purchases. Basically this makes it possible for you to be sure that only a single user of your application is using a single in-app purchase at a time, by validating the signature each time the user launches the app with Apple.