Last updated: 11 September 2026
The short version. The app keeps your diary on your phone — we never receive it. This website collects one thing: the email address you give us for the waitlist. That's it. No tracking cookies, no ad networks, no data brokers.
Deck & Diary is an independently developed mobile application, operated by an individual developer based in China ("we", "us"). For the purposes of the EU/UK General Data Protection Regulation we are the data controller for the personal data described below.
Contact: zhanghr404@gmail.com
| Data | Why | Lawful basis |
|---|---|---|
| Your email address | To send you one email when the app launches, including your early-member discount | Consent (GDPR Art. 6(1)(a)) |
| Which pricing option you clicked, and which link you arrived from | To understand which plan people actually want, and which channel brought you here | Legitimate interests (Art. 6(1)(f)) — aggregate product research |
| Your IP address | Passed to our email provider solely for spam and abuse prevention | Legitimate interests (Art. 6(1)(f)) — service security |
We do not ask for your name, phone number, address, or payment details on this site. We do not use advertising cookies or third-party trackers. We do not sell or rent your data to anyone, for any purpose.
The app is designed so that we collect as little as possible:
Waitlist addresses are stored with a third-party email service provider acting as our data processor, under a data processing agreement. That provider currently is Buttondown (Buttondown LLC, United States). If this changes, this page will be updated before any further email is sent.
This means your email address may be transferred to and stored in the United States. The transfer relies on the provider's standard contractual clauses and equivalent safeguards.
This site is hosted by Vercel Inc., which processes standard server request logs (including IP addresses) on our behalf for security and reliability. We use Vercel's privacy-friendly, cookieless analytics to count visits. It does not set cookies, does not fingerprint you, and does not build a profile of you across sites.
If you are in the EEA, the UK, Switzerland, or a jurisdiction with similar laws, you have the right to:
We will respond to any request within 30 days. You also have the right to lodge a complaint with your local data protection supervisory authority.
To exercise any of these rights, email zhanghr404@gmail.com with the subject line "Data request". We will confirm and delete within 30 days.
This site is served over HTTPS. Waitlist submissions are transmitted over TLS. Access to the waitlist is limited to the developer and protected by the email provider's account security. No system is perfectly secure, but the amount of data at risk here is deliberately minimal: an email address.
This site and the app are not directed at children under 13 (or under 16 where local law requires). We do not knowingly collect data from children. If you believe a child has given us their email address, contact us and we will delete it.
If we change how we handle data, we will update this page and revise the date at the top. If the change is material and you are on the waitlist, we will tell you by email before it takes effect.
Deck & Diary is a tool for entertainment and self-reflection. Card interpretations are creative prompts. They are not predictions, and they are not medical, psychological, financial, or legal advice. Nothing in the app or on this site is a substitute for consulting a qualified professional. If you are in crisis, please contact a local emergency service or helpline.