This depends on the situation and how the app(s) are being used. We have listed the use cases based on Apple's Media Services Terms and Conditions below.
Personal Use
If you are using the app for personal use with your personal devices Apple's Terms of Service state:
"You can have up to 10 devices (but only a maximum of 5 computers) signed in with your Apple ID at one time".
This means that if you download an app like Articulation Station Pro Classic or if you purchase an app license in Articulation Station Hive for your personal use you can put it on multiple devices that you own (up to 10).
Professional Use
If you are working in a clinic, school or district the terms are different. Apple's Terms of Use state:
"Individuals acting on behalf of a commercial enterprise, governmental organization or educational institution (an “Enterprise”) may download and sync non-Arcade Apps for use by either (i) a single individual on one or more devices owned or controlled by an Enterprise; or (ii) multiple individuals on a single shared device owned or controlled by an Enterprise. For the sake of clarity, each device used serially or collectively by multiple users requires a separate license."
SLPs working in a clinic, school, or district that use our app(s) must have their own, separate copy of the app or license to be in compliance with Apple's Terms of Use.
To read the Apple Media Services Terms and Conditions click the link below.
Apple Media Services Terms and Conditions