You can ask for your KinBounty account and its personal data to be deleted, whether or not the app is still on your phone. Nothing is deleted for 30 days, and you can change your mind at any time in that window.
The fastest way is in the app itself. Settings is in the three-dot menu at the top right of every screen: open KinBounty, tap that menu, then Settings → Your data and account → Delete my account. A child does not delete their own account — that page says to ask a parent instead.
A parent deletes a child's account from Settings → Your family → Members: open the child, then the button on their page that names them, Delete [name]’s account. A parent deletes the whole family from Settings → Your data and account → Delete this family.
You do not need to reinstall it. Email support@kinbounty.com with the subject “Delete my KinBounty account”, sent from the email address on your KinBounty account. We only act on requests we can verify: we will send a separate email to the address on your account, and nothing starts until you answer that email.
A child's account is requested by their parent: children sign in with a username only, so a deletion request for a child must come from a parent in the same family, from the parent's own account email.
Two kinds of record survive a deletion, and neither identifies you by name, email or phone number: