Privacy Policy

In short

Who is responsible

Luften is developed by Marco Lüthi, the controller responsible for data processing under the Swiss Federal Act on Data Protection (FADP) and, where applicable, the EU General Data Protection Regulation (GDPR).

Marco Lüthi
Gutstrasse 172
8055 Zürich
Switzerland
hi@luthi-mar.co

Permissions the app asks for

Every permission is optional. Luften still gives advice without any of them.

• Home, to read the temperature and humidity sensors in the Home app. Without it, Luften estimates your room's temperature.
• Location, while using the app, to look up your home address and to point the compass at true north while you set which way your window faces. Without it, you can search for your address by hand.
• Notifications, to tell you when the advice changes.

You can change each permission at any time in Settings.

Home sensors

With Home access, Luften reads the current temperature and relative humidity from the sensors you choose: all sensors, one room or a single sensor. It only reads these values and never changes anything in your home. iOS allows this only while Luften is open. The app shows the names of your homes, rooms and sensors so you can pick one, and remembers your choice and the latest reading on your device, so the widget can show it.

If you set up the Shortcuts action “Update Indoor Temperature”, your automation passes a temperature (and, if you like, the humidity) to Luften, which saves it on your device in the same way.

Your address and location

Luften needs one place: your home. You set it by searching for an address or by tapping “Use Current Location”. While you type, the search text is sent to Apple's map service to suggest addresses. With “Use Current Location”, Luften asks for your position once and has Apple turn it into an address. The address and its coordinates are then saved on your device. Luften doesn't follow where you go: the weather is always for the saved address, also in the background.

While you set which way your window faces, the compass uses your rough position to correct for the difference between magnetic and true north. That position is not stored.

Weather from Apple

Luften gets the current weather and the forecast from Apple Weather (WeatherKit). To do so, the coordinates of your saved address are sent to Apple's weather service, when you open the app and when iOS runs its background refresh. Apple processes this request under its own privacy policy (apple.com/legal/privacy). The data sources are listed on Apple's weather attribution page, which the app also links to in its settings. The weather is kept on your device so the widget can show it.

Notifications and background refresh

If you allow notifications, Luften checks the weather in the background as often as iOS lets it and notifies you when the advice changes. The notifications are created on your device; they don't pass through any server of the developer. They show the advice and the temperatures outside and inside, so they can appear on your lock screen. When you start the airing timer, its countdown is shown as a Live Activity on your lock screen and in the Dynamic Island, and a reminder to close the window is scheduled on your device. Neither passes through any server of the developer.

What is stored on your device

Your home address, sensor choice, window direction, comfortable temperature, unit and notification setting, together with the latest readings, the weather and a log of your airings (when and how long, kept for two days), are stored in an area of your device shared by the app and its widget. They may be included in your device backups, depending on your own iCloud or computer backup settings. Deleting the app deletes all of it.

Legal basis

Where the GDPR applies, the processing described above happens on your device or is a request to Apple that is necessary to provide the features you use (Art. 6(1)(b) GDPR). Home, location and notification access are based on your choice to grant them, which you can withdraw at any time in Settings. Under the Swiss FADP, we process personal data only as described here and in line with its principles.

What the app does not do

• No account, sign-up or login.
• No uploading to the developer: your address, readings and settings are never sent to the developer or to any server of the developer.
• No tracking of where you go, and no iCloud sync.
• No advertising, analytics, crash-reporting or tracking SDKs.
• No tracking across apps or websites, and no selling or sharing of data with data brokers.

This website

This website is a static site without cookies, analytics or tracking. Fonts are served from this website itself, so your browser does not contact third-party font services. When you visit a page, the hosting provider Vercel Inc. (based in the United States, with data centres worldwide) automatically records technical access data in server logs: your IP address, date and time, the requested page, referrer and browser type. This is needed to deliver the site and keep it secure (legitimate interest, Art. 6(1)(f) GDPR). The logs are deleted after a short period. Links to the App Store take you to Apple, where Apple's privacy policy applies.

Your rights

You have the right to request access to your personal data and to have it corrected or deleted, to object to or restrict processing, and to data portability. Because the apps store your data on your device and do not identify you, the developer usually holds no personal data about you. Most of it you can delete yourself by deleting the app.

To exercise your rights, email hi@luthi-mar.co. You can also lodge a complaint with a supervisory authority: in Switzerland the Federal Data Protection and Information Commissioner (FDPIC), in the EU the data protection authority of your country.

International transfers

Apple may process data in the United States and other countries. Apple describes the safeguards it uses for these transfers, such as the Data Privacy Framework and standard contractual clauses, in its privacy policy. This website is hosted by Vercel Inc., based in the United States; its server logs are transferred under the same kind of safeguards.

Children

Luften is not directed at children.

Changes to this policy

If the app starts handling data differently, this page will be updated before the change ships, and the date at the top will change.