You can sign up for subscriptions for channels either through Roku or independent of Roku through the different apps, it makes really no difference. You use whatever login credentials to the apps that you used when you created accounts with those apps. As long as you use what login you used for the app, you can view them anywhere, unless the app has some particular restriction for location or number of devices you can stream. Think of a Roku device as kind of like a streaming cable box that allows you to get whatever channels you want to view.