Procreate must be purchased from the App Store to be used. Any device that supports the App Store, such as iPads, iPhones, and iPod touch, can purchase the app for $9.99. If you've already paid for the app, you can use it free on any computer or mobile device associated with your Apple ID. It's vital to understand that even if the software is a one-time payment, certain features and functionalities can call for further in-app purchases. The use of the app is not conditioned on making these in-app purchases. In conclusion, Procreate is not a monthly subscription service; to use it, you must first buy the software from the App Store.