iReal Pro is a one-time purchase, with no subscription and free updates.
 
The iOS, Android, Mac, and Windows versions are separate products, each sold through its own store: Google Play and the Amazon Appstore for Android, the Microsoft Store for Windows, and Apple's App Store and Mac App Store for iPhone, iPad, and Mac. Each store has its own billing, so a purchase in one cannot move to another, and Apple's App Store and Mac App Store do not connect either. To use iReal Pro on another platform, buy that platform's version.
 
Within a single store, one purchase covers all your devices. Sign in with the same account and install iReal Pro on each of them at no extra cost.
 
For more, see Buy iReal Pro and use it on your devices on the iReal Pro website.