Privacy policy

Updated October 3, 2026. This policy covers the waitlist on calculatorduo.com and calculatorduo.nl.

What we store

When you sign up with consent, we store your email address, signup date, language, signup page, consent version, and a secure removal token in a Cloudflare D1 database. Your email is converted to lowercase to prevent duplicate signups.

How we use your information

We use this information to send Calculator Duo launch updates and manage your signup. We do not sell the waitlist. Signing up is not a purchase and does not guarantee early access.

Hosting and security

Cloudflare hosts the website and processes signups. Cloudflare processes technical connection information to deliver and secure the site. We use your IP address briefly to limit spam; we do not store it in the waitlist database. This site uses no advertising pixels or analytics cookies.

Leaving the waitlist or requesting deletion

After a new signup, we show you a private removal link. Save this link. Open it and confirm removal to delete your email from the waitlist. You can also email corne@messagebull.com from the address you signed up with to request removal, access, or a correction. Use the subject “Calculator Duo privacy.”

How long we keep your information

We keep the waitlist while it is needed for launch updates, or until you unsubscribe. If the waitlist is retired, we delete its records. Any technical backups follow Cloudflare's retention periods.

Questions

Calculator Duo is being developed by Corné van Willigen. Contact corne@messagebull.com with questions about this waitlist. A separate app privacy policy will be available at launch.