Support
development@eggsandoats.com
It helps to say which iPhone and iOS version you have, and what you were doing when it went wrong. A screenshot helps too.
Subscriptions
Apple handles billing. To change or cancel, open Settings on your iPhone, tap your name, then Subscriptions. In Puffy, the same screen is under Profile, then Settings.
Your data
You can delete your account, and the data with it, in Puffy under Profile, then Settings, then Delete Account. To ask what we hold about you, email us from the address on your account.