Updated 25 September 2026

Privacy policy

CardIQ is made by Charlie Horton, an independent developer in the UK ("we", "us"). This policy explains what the app collects, why, and the choices you have. The short version: you can play without an account, there are no ads, we don't track you across other apps, and you can switch off analytics.

Playing as a guest

Without an account, your progress (XP, Market IQ, streaks and stats) is stored only on your device. We never receive it, although the app sends the usage and crash data described below unless you turn it off.

The app downloads card prices from our server. That request contains no personal information, although our hosting provider processes your IP address to deliver it, as any website does.

If you create an account

Accounts are optional and are only needed for the Daily leaderboard and for syncing progress between devices. You can sign in with Apple or Google.

We store:

your email address
an account ID
your name, if your Google profile provides one
an automatically generated username
your progress: XP, level, Market IQ, streaks, games played, cards priced and accuracy
your game history: the mode you played, the cards you priced, your guesses, your scores and when you played

Other players see your username, Daily score and accuracy on the leaderboard. Nothing else about you is public.

We use this information only to run your account and the game. The legal basis is providing the service you asked for.

Usage and crash data

To find bugs and see which parts of the game people enjoy, the app sends usage and crash data to PostHog, our analytics provider:

the screens you open and the games you finish: mode, score, number of cards, time taken and average accuracy
your level, Market IQ, XP, streaks and games played
sign-ins and sign-ups (which provider you used, not your email address or name) and shares of your Daily result
crash reports and error details
your device model, operating system, app version and language
your approximate location (country and city), worked out from your IP address. The IP address itself isn’t stored
a random ID for this installation of the app. If you sign in, it’s linked to your account ID
during some sessions, a recording of the app’s screens and taps, so we can see where people get stuck

The legal basis is our legitimate interest in keeping the app working and improving it. We don’t use this data for advertising or share it with anyone else. You can turn it off at any time in Profile → Share usage and crash data.

What we don’t do

We don’t show advertising, track you across other apps or websites, or sell or share your data for marketing.

Who processes your data

Supabase hosts our database, sign-in and file storage.
PostHog receives the usage and crash data above. It’s stored in the EU (Frankfurt).
Apple and Google handle sign-in when you choose them.
PokePulse provides card prices. No personal information is sent to them.

Keeping and deleting data

We keep account data until you delete your account. You can delete it at any time in the app under Profile → Delete account. This permanently removes your account, your leaderboard entries and your synced history.

PostHog keeps usage and crash data for a limited period. Deleting your account doesn’t delete it straight away, but it’s no longer linked to anything that identifies you. If you’d like it deleted sooner, email us.

To clear progress stored on your device, use Profile → Reset progress, or delete the app.

Your rights

Under UK data protection law, you can ask to access, correct, export or delete your data, or object to how we use it. Email charliehorton.dev@gmail.com and we’ll reply within one month. You can also complain to the Information Commissioner’s Office.

Children

CardIQ is not directed at children under 13, and we don’t knowingly collect personal information from them. If you believe a child has created an account, contact us and we’ll delete it.

Changes and contact

If this policy changes, we’ll update the date above. For significant changes, we’ll also tell you in the app. For questions, email charliehorton.dev@gmail.com.