We do not collect any personal data at all. All your app data is either being stored in iCloud Drive linked to your iCloud account or locally on your device. The only things that get collected are the crash reports and purchases, however, they are not linked to you in any ways.
We use ConvertKit platform to offer DesignTech Apps Newsletter which may collect the information, such as, but not limited to, first name and email address. You can read the privacy policy of ConvertKit here: convertkit.com/privacy.