The app itself is fantastic and I don't mind paying for it. However it is not possible (as far as I can tell) to use the app once signed up on a child's profile. I have tried numerous times to allow access to the fully subscribed app on Kindle Kids and now Google Play Family Library and it just won't acknowledge that the app has been paid for. Incredibly frustrating. It’s a kids app which doesn't seem to be able to be played on a child safe profile.