Privacy

Updated 21 October 2026

Sector4 never asks you for an account, a name or an email address. The app only counts how people play, under a random number, to learn what players enjoy and what is too hard. You can switch this counting off at any time in the settings.

Who is responsible

The Sector4 app and the sector4.app website are published by Sarah Guignes, as an individual. For any question about your data, write to contact@sector4.app.

What the app sends

When you finish a round, the app records:

• the day, the game mode, the pack and the language;
• how long the round lasted;
• for each question, which question it was, whether it was found, missed or skipped, and how long the answer took;
• in Duel, whether the answer came from Player 1 or Player 2, never your names.

A round you abandon sends nothing.

When you visit the Shop, the app records that you opened it, which pack page you looked at, whether you started the trial, and whether a purchase was started, completed or cancelled. It never sees your payment method.

Each upload also carries:

• a player number, drawn at random on your phone, with no link to your Google account or advertising ID. It is replaced with a new one every 12 months;
• the app version;
• the country the upload comes from, worked out from your IP address by our host. The IP address itself is never stored.

This information cannot tell anyone who you are. Because it is tied to a number, the law still treats it as personal data, which is why this page describes it.

Why

The number links together the games of the same player. That tells us how many people play, whether they come back from one week to the next, which questions are too easy or too hard, and whether a pack someone looked at ends up being bought. Nothing else.

This counting relies on our legitimate interest in improving the game. It is on by default and you can object to it at any time.

What the app does not do

• No advertising and no ad profiling.
• No analytics or tracking tool from a third party.
• No access to your location, contacts, photos, microphone or camera.
• Heads-up reads the tilt of the phone to confirm or skip a card. That movement stays on the phone.
• Your records, history, settings and Duel names stay on the phone.
• No data is sold or shared.

How long

The data received is deleted automatically after 25 months. The player number changes every 12 months, so two periods cannot be linked together.

Where it is kept

Uploads are received and stored by Cloudflare, our host, in a database kept in the European Union. Cloudflare acts on our behalf and does not use the data for itself. In transit, uploads may pass through Cloudflare servers outside the Union. These transfers are covered by the EU-U.S. Data Privacy Framework, which Cloudflare has joined.

How to say no

In the app settings, turn off Usage statistics. The app then deletes its number and anything waiting to be sent, and nothing more leaves your phone.

Data already sent stays tied to the old number until it is deleted automatically. To have it deleted sooner, note the start of the number shown in that setting before turning it off, then write to us.

Your rights

You can ask to access your data, to have it deleted or restricted, and you can object to its processing. Since we do not know who you are, include the start of your player number, shown in the app settings, with your request. We reply within one month.

If you believe your rights are not respected, you can complain to the CNIL, the French data protection authority, or to the authority in your country.

Notifications

The app can let you know before each Grand Prix and when a new pack comes out, only if you agree, in the “Want a heads-up?” window or in the settings.

• Grand Prix reminders: they are scheduled on your phone. Nothing is sent.
• Sector4 news: your phone receives a delivery identifier from Google (Firebase Cloud Messaging), specific to the app on that phone. The app sends it to our server with your language, so we can announce new packs. It is linked neither to your player number nor to your games. When you turn this setting off, the app deletes it from our server.

Announcements go through Firebase Cloud Messaging, a Google service acting on our behalf. The identifier is kept at Cloudflare, in the European Union, for as long as the setting stays on.

Google Play and Android

Purchases go through Google Play. Google handles the payment under its own rules. The app only receives confirmation that a pack is yours.

If Android backup is on for your phone, Google may copy your settings, records and history to it, in your Google account. The player number is never backed up. If you have agreed to share crash reports with developers, Google sends us anonymous reports when the app crashes.

These are governed by Google's privacy policy.

The sector4.app website

The website sets no cookies and does not measure its audience.

Changes

If the app starts collecting anything else, this page will be updated beforehand, with its new date at the top.