Itunes GC def do
@EJB Frequency and severity? More often than Google Play?
I think if you buy via Apple you can also download on Android if it's linked to the same Artscroll account. Cmiiw.
ETA: I don't think that you actually buy the volumes on GP. They have the library app on Play Store and you need to buy the volumes from Artscroll.com. Similar in Apple world?