N-Back Privacy Policy

Introduction

N-Back ("the app") is developed by Grisu Studio. This policy explains exactly what the app stores, what it sends, and what it never touches. The app has no accounts, no login and no servers of ours: everything you create in it is written to your own device and stays there. The only data that leaves your phone is what Google's advertising SDK sends in order to serve the ads that keep the app free, and you control whether that is personalised.

Scope

This privacy policy applies solely to the N-Back mobile application.

Data We Collect

Stored on your device only, never transmitted to us: your sessions, including per-beat results, scores and the N level you played; your daily-challenge state, streak and awards; and your settings (language, N, mode, beats, interval, auto-level, daily target, sound and haptics). We also store the answer to the one-time age question as a bracket only — either "under 13" or "13 or over". The birth year you enter is converted to that bracket and immediately discarded; the app never stores a date of birth. Collected by Google AdMob, not by us, in order to serve ads: your device advertising identifier (IDFA on iOS, Advertising ID on Android), IP address, coarse device information such as model and operating system version, and ad interaction data. We never collect your name, email address, phone number, contacts, photos, precise location, or any account identifier — the app asks for none of them and has nowhere to send them.

How We Use Your Data

Your on-device data is used only to make the app work: to score the session you just played, decide whether to raise or lower N, and draw your level-over-time chart. It is never uploaded, never shared and never analysed by us: there is no analytics SDK and no crash-reporting service in N-Back, so we genuinely cannot see how you use it. Advertising data is used by Google to deliver and measure ads. In the European Economic Area and the United Kingdom the app shows Google's consent form before any ad loads, and on iOS it shows Apple's App Tracking Transparency prompt. If you decline either one, ads still appear but are non-personalised. You can revisit and change these choices at any time from Settings → Privacy and ads. The app also caps the content rating of every ad it requests, so ads for gambling, alcohol, dating and similar adult categories are excluded regardless of your consent choices.

Children's Privacy

N-Back is rated and listed for people aged 13 and over, and is not directed to children. Working-memory training is used by students as much as by adults. The app additionally asks a neutral, skippable age question on first launch. If you indicate you are under 13, the app switches to child-directed treatment for the rest of its life on that device: ads are restricted to the "General audiences" rating, are never personalised, no advertising identifier is used, and Apple's tracking prompt is never shown. This setting can be changed at any time in Settings → Privacy and ads, so a parent handing over a phone can tighten it without reinstalling. We do not knowingly collect personal information from children, and the app has no mechanism to do so — there is no account, no messaging and no upload of any kind.

Data Security

Because we run no servers and hold no database, there is no copy of your data anywhere for us to lose. Everything N-Back stores lives in the app's private storage on your device, protected by the operating system's own sandboxing and by whatever device encryption you have enabled. Uninstalling the app permanently deletes all of it, and Settings also offers a reset that clears your saved data without uninstalling. Data handled by Google AdMob is governed by Google's own privacy policy at policies.google.com/privacy.

Changes to This Privacy Policy

We will update this policy whenever the app's behaviour changes in a way that affects it, and the "Last Updated" date above will change with it. Material changes will also be noted in the app's release notes. Continuing to use the app after an update means you accept the revised policy.

Contact Us

Questions, corrections or a request to delete data: email support@grisu.co with "N-Back privacy" in the subject. Because all of your data is held on your own device, a deletion request is fulfilled by uninstalling the app or using the reset option in Settings — we hold nothing to delete on our side, and we will say so plainly if you ask.

Company Privacy Policy

For our general company privacy policy, see Grisu Studio.