If a person transfers to another phone can they still use the remaining part of a paid subscription

Hi gbpackergold,

Unfortunately the subscriptions cannot be transfered from one store to another yet. We're working on changing that in the future but we don't have the details on that yet. 

What you need to do now is to cancel the yearly subscription from the Apple iTunes (if you're no longer using Apple devices where you'd use our product) and make a new subscription to Google Play store.