Before you write
You can delete your account yourself, from the app's settings. For a copy of your data, use this form. Bookyard Plus is billed by Apple, so refunds come from Apple too: see Subscriptions & Refunds.
How long we take
Usually a few days. Requests about your data are answered within 30 days at the latest, as the Privacy Policy promises.
Who you are writing to
M.A.K. PFA, who runs Bookyard and is the data controller named in the Privacy Policy.