PlayScore subscriptions are sold separately by Google, Apple and Microsoft. Each applies to that platform only as these companies do not recognise each others’ subscriptions.
However, any PlayScore document you create with a subscription can be played on any device using the free PlayScore download, without a subscription. You won’t be able to create new documents without a subscription, but you will be able to play the music, adjust tempo, create loops and use the count-in/metronome (iOS and Windows only).
For example you can have a subscription on your phone or tablet where you create new documents. Then you can email those documents to your Windows computer where you can play the music taking advantage of better audio and a bigger screen.