That’s kind of a vague question, but in general you can subscribe to as many services as you like, in as many ways as you like. For example, it’s possible to subscribe to something like Netflix: directly at Netflix, and via Roku, and via Fire TV, and via Android, and possibly a dozen other ways.
So, you have to be careful. If you are already paying some service, and you install that service on some platform that also has a payment system and your payment details in place, then you need to make sure you sign IN to that app, not sign UP for it. The latter will get you charged twice.
If you start a service through some payment platform (Apple, Roku, …) then it is possible you won’t be able to watch it (without additional charges) elsewhere.
Banned but back. Because why not?
