Privacy Policy

1. Who is responsible

The controller for the processing described here, in the sense of Art. 4(7) GDPR:

The full provider identification under § 5 DDG is on the legal notice (Impressum) page. We have not appointed a data protection officer, as we are not required to under Art. 37 GDPR and § 38 BDSG; data protection questions go to the contact address above.

2. The app: everything stays on your phone

Spross is an offline app. It has no server behind it, and the code that would talk to one does not exist: the iOS and watchOS sources contain no network API of any kind, and the Android app does not even declare the INTERNET permission, which means the operating system itself blocks it from opening a connection.

What is stored, and where

Your cards, your answers, your review history and your settings are written to your own device only:

• on iPhone and Apple Watch, into the shared app container group.net.spross.app, which is what lets the widget and the watch app show the same box as the phone;
• on Android, into the app's private storage.

We never see any of it. Deleting the app removes this data from the device along with it, and there is no copy anywhere else for us to delete on request — which also means the app itself is your only backup unless your device makes one (see below).

What the app does not do

• no user accounts, no login, no email address, no name;
• no analytics, usage statistics or telemetry;
• no crash or diagnostics reporting to us;
• no advertising, no advertising identifier, no tracking of any kind;
• no analytics, advertising or tracking SDK — the app links the platform UI toolkit (Jetpack Compose on Android) and our own learning engine, neither of which opens a connection;
• no camera, microphone, location, contacts or photo access; the only permissions the Android app declares are the ones "Hear your words" needs — audio settings, a media-playback foreground service, a wake lock, and the notification that carries the run's controls.

Between your own two devices

iPhone and Apple Watch keep each other up to date through Apple's WatchConnectivity, which passes the data directly between the two paired devices over Bluetooth or the local network. It does not travel over the internet and it does not reach a server of ours or of Apple's.

Saying words out loud

Recorded pronunciations ship inside the app and are played from it. Where no recording exists, the word is spoken by your device's own speech synthesis:

• iOS/watchOS synthesises on the device. Spross only uses voices already installed; it downloads nothing. If you install a higher-quality voice, iOS itself fetches it from Apple, outside the app.
• Android hands the word to whichever text-to-speech engine you have installed. Some engines, including Google's, may synthesise over the network, in which case the word being practised is sent to that engine's provider under its own privacy policy. Spross makes no such request and cannot observe it — but we would rather name it than let you assume otherwise. Your Android speech settings decide which engine is used.

Device backups

The app sends nothing, but your device's backup may carry the app's data along with everything else:

• iOS includes the app container in an iCloud or encrypted local backup if you have backups switched on.
• Android currently allows Auto Backup, so Android may copy the app's data into your Google Drive.

Both are your device's own function, under your setting and under Apple's or Google's terms — not a transmission by Spross. Turning the backup off, in the operating system's settings, stops it.

3. Getting the app: Apple, Google and GitHub

Spross is distributed outside the app stores at the moment: the Android package is downloaded from our GitHub release page, and the iPhone build reaches testers through Apple's TestFlight or as a direct over-the-air install.

Whoever hands you that download processes data about it — your IP address, the request, and with Apple an account and device identity — as their own controller, under their own privacy policy, not ours. That is true of Apple Inc. and GitHub, Inc. today, and it would equally be true of the App Store or Google Play, including any purchase data, if Spross is ever offered there: that processing is Apple's or Google's, not Polygon GmbH's.

Two things do reach us through those channels, and you should know about them:

• if you take part in the TestFlight beta, Apple shows us the email address you joined with, which builds you installed, and any feedback or crash report you choose to send through TestFlight. We use that only to run the beta and answer you.
• download counts from GitHub and Apple, which are aggregate numbers and identify nobody.

4. This website (spross.net)

Server logs

spross.net is a set of static files with no application server behind them. Like every web server, the host records each request: IP address, date and time, the file requested, the status and size of the response, and the browser's user-agent and referrer. This is processed to deliver the page and to keep the server secure and functioning, on the basis of our legitimate interest under Art. 6(1)(f) GDPR, and is kept only for the short period the host needs for that purpose. Our hosting provider processes these logs on our behalf as a processor under Art. 28 GDPR.

No cookies, no analytics

The site sets no cookies. There is no analytics, no tag manager, no tracking pixel and no advertising. Every file the page loads — stylesheet, script, images, sounds, the learning engine — comes from spross.net itself; no fonts, no CDN and no other external resource is fetched, so no third party learns that you visited. That is also why you are not asked to consent to anything on arrival: there is nothing to consent to.

The counting drill

The drill on the landing page is the app's real engine compiled to JavaScript, and it runs entirely inside your browser. The numbers, your answers and your mistakes are never sent anywhere.

The drill stores one thing in your browser's local storage: your best streak per language, under keys of the form spross.record.numbers.de. It is a number, it contains no identifier, it is never transmitted, and it is only read to tell you when you beat it. We regard this as storage strictly necessary to provide the function you asked for (§ 25(2) no. 2 TDDDG); clearing the site data in your browser removes it.

Speech in the browser

If your browser offers a voice for the language, the drill can read an answer aloud using the browser's built-in speech synthesis. Whether that happens on your device or through your browser or operating-system vendor's service depends on that vendor, not on us; we send nothing ourselves.

The mailing list

The signup form is not connected to a mailing-list provider yet. Submitting it today transmits nothing at all — it only shows a note asking you to write to us instead.

When the list opens, the address you enter will be used solely to send the Spross newsletter, on the basis of your consent under Art. 6(1)(a) GDPR, confirmed by a double opt-in email. The list will be run by a specialist email service provider as our processor under Art. 28 GDPR; we will name that provider here before any address is transmitted to it. You can withdraw your consent at any time, with effect for the future, through the unsubscribe link in every issue or by writing to us, and the address is deleted when you do.

Writing to us

If you email spross@polygon.gmbh, we process your address and whatever you write in order to answer you — Art. 6(1)(b) GDPR where it concerns the app you use, otherwise Art. 6(1)(f). Our email is hosted by a provider acting as our processor under Art. 28 GDPR. We keep correspondence as long as the matter is live and any statutory retention period runs, then delete it.

5. Recipients and transfers outside the EU

We pass personal data to no one for their own purposes. The only recipients are the service providers named by category above — our hosting provider, our email provider, and in future a mailing-list provider — each bound by a data processing agreement under Art. 28 GDPR. Where such a provider processes data outside the EU or EEA, we rely on an adequacy decision of the European Commission or on standard contractual clauses under Art. 46(2)(c) GDPR. Apple, Google and GitHub are not our processors: as described in section 3, they act as their own controllers for what they do.

6. How long we keep things

• App data: we never receive it; it lives on your device until you delete the app.
• Server logs: the short technical period our host needs for delivery and security.
• Mailing list: until you unsubscribe.
• Correspondence: until the matter is settled, subject to statutory retention periods.

7. Your rights

You have, in respect of the personal data we process about you:

• the right of access, Art. 15 GDPR;
• the right to rectification, Art. 16 GDPR;
• the right to erasure, Art. 17 GDPR;
• the right to restriction of processing, Art. 18 GDPR;
• the right to data portability, Art. 20 GDPR;
• the right to object, Art. 21 GDPR, to processing based on Art. 6(1)(f) — on grounds relating to your particular situation, and at any time and without reason where it is direct marketing;
• the right to withdraw a consent you have given, Art. 7(3) GDPR, at any time and with effect for the future, without affecting the lawfulness of what came before.

To exercise any of them, one email to spross@polygon.gmbh is enough; no form and no particular wording is required. We answer within one month, as Art. 12(3) GDPR requires. Note that for the learning data in the app there is nothing for us to disclose, correct or erase, because we hold none of it — it is on your device, and deleting the app deletes it.

8. Right to complain

You can lodge a complaint with a supervisory authority, Art. 77 GDPR, in particular in the Member State of your residence or workplace or of the alleged infringement. The authority responsible for us is:

9. No automated decision-making

We carry out no automated decision-making or profiling within the meaning of Art. 22 GDPR. The app's spacing algorithm does schedule your cards from your own answers, but it runs on your device, produces no decision about you with legal or similarly significant effect, and its results are never seen by us.

10. Changes to this policy

We update this page when the app or the site changes what it does with data — for instance when the mailing list opens. The date at the top always tells you which version you are reading.