Privacy Policy

Arcanalia · Effective 24 October 2026

Arcanalia (“the app”) is made by Esteban Feldman and provided free of charge. It is funded by ads. This policy explains what information the app handles and why.

The camera and your photos

The app uses your camera only while the scanner is open. When you tap to scan, it takes one photo, reads it into memory and deletes the photo file straight away. The card is recognised on your phone by a model built into the app. The photo is never uploaded, kept or shared. You can withdraw camera permission at any time in your Android settings, and the card library keeps working without it.

What stays on your device

The app keeps a little information in its local storage on your device:

your last ten scanned cards, meaning which card it was, whether it was upright or reversed, and when you scanned it;
whether you’ve seen the introduction and the first-scan tip.

There is no account and no sign-up, and the app does not send any of this anywhere. If Android backup is turned on for your device, Android may include this data in your Google backup and restore it when you reinstall. Settings → Clear recent scans deletes your scan history. Uninstalling the app deletes everything from the device, though a copy may remain in your Google backup until that backup is replaced or deleted.

Where the law requires it, for example in the European Economic Area, the United Kingdom and Switzerland, the app asks for your consent using Google’s consent form. It does this once you’ve finished the introduction, the first time you open the app. Your choice decides whether ads may be personalised, and declining also switches off usage analytics. The form appears after the introduction, so usage from your first few minutes may already have been sent. It doesn’t switch off the crash reports described below, which are sent either way. You can change it at any time in Settings → Ad privacy choices. That row appears only where the law requires it.

Advertising (Google AdMob)

The app shows one banner ad, on the library home screen, served by Google AdMob. There are no ads on the scanner or on a card’s meaning. Ads, together with the analytics and crash reports described below, are the only parts of the app that use the internet.

To serve and measure ads, AdMob collects:

your device’s advertising ID;
your IP address, and an approximate location derived from it;
device and app information;
information about how you interact with ads.

Where the law requires it, personalised ads are only shown after you have consented. If you decline, you may still see ads, but they won’t be personalised.

You can reset or delete your advertising ID, or opt out of personalised ads, in your Android settings under Google → Ads (or Privacy → Ads), or at https://adssettings.google.com.

Google explains how it uses data from apps that show its ads at https://policies.google.com/technologies/partner-sites. Google’s privacy policy: https://policies.google.com/privacy

Analytics and crash reports (Google Firebase)

The app uses two Google Firebase services to learn how it’s used and to fix problems.

Google Analytics for Firebase records how the app is used, such as when it’s opened, which screens and features you use, such as how scans turn out, how long you use it and when it’s updated. It never records which card you scanned or viewed, or anything you type. With this it sends:

a random ID for this installation of the app;
your device’s advertising ID;
device and app information, such as the device model, Android version, language and app version;
your IP address, which Google uses to work out an approximate location, such as your country or city.

Firebase Crashlytics sends a report when the app crashes or runs into an error it recovers from. A report contains:

the technical details of the error and the state of the app at the time;
device information, such as the model, Android version, free memory and storage, and whether the device is rooted;
a random ID for this installation of the app, used to count how many people a crash affects.

Neither service receives your photos, your scan history, your name or your email address. The developer uses this data to understand and improve the app. Google Analytics is linked with AdMob, so Google can use it to measure how well ads perform.

Analytics runs from when you first open the app. Where the consent form applies, declining switches it off, and you can change your choice in Settings → Ad privacy choices. Elsewhere it runs whenever the app is open. Crash reports are sent whatever you chose, because the developer has a legitimate interest in fixing faults, and the app has no setting to turn them off. You can reset or delete your advertising ID in your Android settings under Google → Ads (or Privacy → Ads). Uninstalling the app stops all collection and removes its random IDs from your device.

Google explains how Firebase handles data at https://firebase.google.com/support/privacy.

Google Play also gives the developer aggregate statistics, such as install counts. If you’ve allowed your device to share usage and diagnostics with Google, Play also sends the developer anonymous crash reports.

Feedback email

Send feedback in Settings opens your email app with a message addressed to the developer. If you send it, the developer receives your email address, your message and the app version in the subject line, and uses them only to reply to you.

Share opens Android’s share sheet, and Rate opens Google Play. More apps and Privacy policy open web pages. These services are run by Google or by others, and their own privacy policies apply. The developer has no control over them, and takes no responsibility for their content or their privacy practices.

Who receives data

The only third party the app shares data with is Google, which provides AdMob and Firebase. The developer never sells your data.

Data retention and deletion

Google keeps AdMob data according to its own retention policies. Analytics data tied to an installation’s random ID is deleted after at most 14 months, and crash reports after 90 days. The developer can see this analytics and crash data, but it isn’t linked to your name or email address, so the developer can’t pick out or delete one person’s records. Apart from that, the developer holds only the feedback emails you choose to send. You can ask for those emails to be deleted by writing to the address below.

Security

Reasonable measures are used to protect the information the app handles, but no method of transmission over the internet or of electronic storage is completely secure.

Children

The app is not directed at children under 13, and does not knowingly collect personal information from them. If you believe a child has provided personal information, contact the address below and it will be deleted.

Changes to this policy

This policy may be updated when the app changes. Changes are posted on this page, and the effective date above shows when it last changed.

Contact

Questions about this policy: esteban.feldman@gmail.com