Privacy policy
Lanterna · Last updated: 28 October 2026
Lanterna (“the app”) is published by Lanterna Konsult AB (reg. no. 559568-9893), Nunnebanan 30, 618 95 Stavsjö, Sweden (“we”). This policy explains what information the app handles. In short: we do not collect any personal data, unless you choose to send us a problem report. The app sends anonymous usage statistics that cannot be linked to you.
No account, no tracking
The app works without an account or login. It contains no advertising and no third-party analytics or tracking tools, and it does not ask for access to your contacts, location, camera, microphone or files.
Anonymous usage statistics
To see whether the app is used and which parts are useful, the app tells our own server (hosted by Netlify) when it is opened (at most once a day), when an exercise is started, finished or left before the end, when a question is shared as a picture, when Google Play’s rating box is opened, when a category is hidden from the start page or shown again, and the steps of a purchase (the unlock page shown, the buy button pressed, bought or not bought). Each message contains only: what happened, the study category and type of exercise, the result or how far you got in tens of percent, the number of questions or cards in the exercise, when the app is opened the buoyage region and the light or dark look you chose, the app version, the kind of device (for example “iPhone” or “Google Play app”), the language your phone is set to (for example “en”), roughly how long ago the app was first opened on the device (first day, first week, first month or longer) and, if you came through a link with a campaign code, that code. At the end of an exercise it also sends which questions were answered right or wrong (only the question numbers), so we can find unclear questions. The server adds the country, worked out from the connection, and the time. Each message also carries a random number that the app makes up on your device and replaces with a new one every day, so we can see how much one device used the app on a single day. The numbers of different days are never linked, and the number is removed from the statistics after 30 days. We do not store your IP address, and the app sends no name, account, advertising ID, hardware identifier or cookie, so the statistics cannot be linked to you. They are only used to improve the app and are only seen by us.
Access codes for the web version
If your school or we gave you an access code, the web version sends the code to our server when you enter it and each time the app starts with a connection, to check that it is still valid. With it, the app sends a random licence number that it makes up on your device, so that a licence can be limited to a number of devices and the same device is not counted twice. We store only the code, that number and the days it was first and last used. The licence number is never sent with the usage statistics and is not linked to them, and it is deleted 90 days after the licence has ended. The Google Play app never sends it.
On a device unlocked with a code, the anonymous usage messages described above also carry that code (never the licence number), so that the school can be given a usage report with totals for its code: how many questions were answered and how many were right per topic, and how many exercises were started and completed. These totals are stored without the daily device number and without the country, contain nothing about a single student, and are deleted together with the licence numbers.
A school can choose to show its own name, logo and colours in the app on the devices that use its code. The server then sends them with the code check, and they are kept on your device so they also show offline. They are removed from the device when the code stops working. Nothing about you is sent for this.
Data stored on your device
Your settings (your region, the light or dark look and the categories you have hidden) and your study progress (which questions you have answered right or wrong) are saved in the app’s local storage on your own device. Your results and study tips on the progress page are worked out on the device from this information. The stored information itself is never sent to us or to anyone else – only the anonymous usage messages described above, which include the region and look when the app is opened, a note when a category is hidden or shown again, and which questions were answered right or wrong in an exercise. You can delete the stored information at any time by clearing the app’s data or uninstalling the app.
Problem reports
If you choose to send a problem report from the app, we receive what you write, the reason you pick, the question it is about (with the right answer and the answer you chose) and the app version. The app adds nothing else – no name, e-mail address or device identifier – but our hosting provider (Netlify Forms) also records the IP address and browser type with each report, as web servers do. Reports are only used to fix the app and are deleted when they have been dealt with. If you send the report by e-mail instead, we also receive your e-mail address, and use it only to reply to you.
Deleting your data
You do not need an account to use Lanterna, so there is no account to delete. What you can do:
- Data on your device (settings, progress, purchase status): clear the app’s data or uninstall the app. A purchase on Google Play is kept by Google and comes back when you reinstall.
- Problem reports: e-mail robin_rantala@lanternakonsult.se with the subject “Lanterna data deletion” and roughly when you sent the report and what it was about. We delete it within 30 days and confirm by e-mail.
- Anonymous usage statistics contain nothing that can be linked to you. The daily random number stays on your device only until it is replaced the next day you use the app, and on our server for at most 30 days, so we cannot find statistics from a particular person. Clearing the app’s data also clears the number. The statistics are kept only as long as they are useful for improving the app.
Hosting
The web version of the app is delivered by a hosting provider (Netlify). Like any web server, the provider may briefly record technical information such as IP address and browser type in server logs, to deliver the app and keep the service secure. We do not use this information to identify you.
Purchases
If you buy access to extra content in the version on Google Play, the payment is handled entirely by Google Play under Google’s own privacy policy. We receive confirmation that a purchase was made, but never your payment details.
Children
The app is made for maritime students and is not directed at children under 13. Since we collect no personal data, no data about children is collected either.
Changes
If the app changes in a way that affects your privacy – for example if we add a feature that sends data – we will update this page before the change takes effect and show the new date above.
Contact
Questions about privacy: robin_rantala@lanternakonsult.se