Apps
If the setting “Share with app developers” in the macOS System Settings under Privacy & Security > Analytics & Improvements is enabled, crash reports which are not linked to the user are stored by Apple and forwarded to me for the only purpose of fixing issues within the apps.
Website
When leaving a comment, the IP address and browser user agent string are saved along with the user-provided data. The name and comment can be made public unless requested otherwise; the other data, including the email address, are not shared. The user can request a copy or the deletion of their own data stored on my servers by using the contact form. A cookie is created to keep showing the comment to the user while it is held in moderation queue.