Privacy policy

Last updated: 27 October 2026

This policy covers the app Smart Sudoku Zen for iPhone and iPad and this website, sudoku.smartbyte.app.

Who is responsible

Smart-Byte GmbH
Landshuter Str. 29
85435 Erding
Germany

Represented by Mario Heubach. Phone +49 (8122) 5676-141, email info@smart-byte.com.

The app in short

Smart Sudoku Zen needs no account, shows no ads, does not track you and contains no analytics. We run no server for the app, so we receive nothing about how you play.

Data on your device

Your progress, coins, statistics and settings are stored on your device and in its backups. If you enable iCloud sync in the app, a copy of your game progress, including coins, statistics and the current puzzle, is also stored in your private iCloud database. Devices using the same Apple Account can sync this save. Language, sound switches, reminders and the app icon stay local. Disabling sync keeps both saves; deleting the app removes its local data but does not delete the iCloud save.

Game Center

If you are signed in to Game Center, the app reports your scores and achievements to Apple so they appear in the leaderboards and your Game Center profile. Apple processes this data under its privacy policy. If you are not signed in, nothing is reported.

Camera and photos

Only when you choose to photograph a sudoku or pick a photo, the image is analysed on your device to read the grid. It is neither stored nor sent anywhere. The photo picker gives the app only the photo you select, not your library.

Notifications

If you allow notifications, the daily reminder is scheduled on your device. No server is involved.

App Store, purchases and ratings

The app is sold through Apple's App Store, Apple handles the payment. The rating prompt is shown by iOS. Apple gives us aggregated download and sales figures and, if you agreed in your device settings to share analytics with app developers, aggregated usage and crash statistics. None of this identifies you.

This website

Hosting

We serve this website through Google's Firebase Hosting. Requests involve connection data such as your IP address and request details to deliver the pages and to detect abuse. Our legitimate interest is a reliable and secure website (Article 6(1)(f) GDPR). Google states that Firebase Hosting keeps IP data for a few months; processing may take place outside the EU. Recipients and safeguards, including standard contractual clauses, are described in the Firebase privacy information and the Firebase data processing terms.

Cookies and local storage

The website sets no cookies. It stores only your language choice in your browser's local storage so the next page opens in the same language; this is strictly necessary for the function you chose (section 25(2)(2) TDDDG). The mini puzzle, its sounds and the 3D garden run entirely in your browser. Apart from the visit counter below, all fonts and files come from this website. Links to the App Store lead to Apple.

Website statistics with Umami

We count visits with Umami, open-source analytics that we run ourselves at analytics.smart-byte.com on a server of Hetzner Online GmbH, Industriestr. 25, 91710 Gunzenhausen, Germany, located in Finland. Hetzner processes this data on our behalf under a data processing agreement (Article 28 GDPR); nobody else receives it.

When a page loads, your browser loads a small script from there and sends the page's address and title, the page you came from, your screen size and browser language. When you tap a link to the App Store, it also sends which of these links it was. From your IP address and browser type, which every request carries, our server works out your browser, operating system, device type and approximate location (country, region and city).

Umami sets no cookies and stores nothing on your device. It does not store your IP address: to tell visits apart, it derives a pseudonymous identifier from your IP address, your browser's user agent and a salt that changes every day, so visits cannot be linked across days. We look at the results only in aggregate and build no profiles. Our interest is improving the website (Article 6(1)(f) GDPR). Analytics records are deleted after 13 months. Browsers that send Do Not Track are not counted.

Contact by email

If you write to us, for example through the support page, we use your email address, your message and any attachments, such as the device and iOS version you mention, to handle your request. For questions about a purchase or a contract the legal basis is Article 6(1)(b) GDPR, otherwise our legitimate interest in answering you (Article 6(1)(f) GDPR). We keep the correspondence as long as it is needed to handle your request or to meet statutory retention duties.

Your rights

Under the GDPR you may request access, rectification, erasure, restriction and data portability, and object to processing based on legitimate interests. Write to info@smart-byte.com. You may also complain to a supervisory authority; ours is the Bavarian State Office for Data Protection Supervision.