Privacy policies for apps published by freethinker AG / Peter Greis.
Effective date: 18 June 2026
DICOM Viewer is a native macOS application for opening and reviewing DICOM (.dcm) medical imaging files.
Nothing.
DICOM Viewer collects no personal data, no usage analytics, no crash reports, no identifiers, no telemetry. The app does not contain any third-party SDKs that collect data on our behalf.
Nothing.
DICOM Viewer makes no network connections of any kind. It does not contact a server, does not check for updates, does not phone home. Your DICOM files and any annotations or measurements you create stay on your Mac.
Only on your Mac, in files you choose. The app only reads files you explicitly select through the standard macOS file picker. Exported files (PNG screenshots, extracted PDF documents) are written only to locations you choose through the standard macOS save dialog.
The app is sandboxed (com.apple.security.app-sandbox) with the minimum entitlements required to read user-selected files and to save user-selected exports. It has no entitlements granting access to the network, the camera, the microphone, contacts, calendars, photos library, location, or any other personal data on your Mac.
The app declares zero use of Apple's "required-reason" API categories in its bundled PrivacyInfo.xcprivacy manifest:
NSPrivacyTracking:falseNSPrivacyTrackingDomains: emptyNSPrivacyCollectedDataTypes: emptyNSPrivacyAccessedAPITypes: empty
DICOM Viewer is not directed at children under 13 and does not knowingly collect any data from anyone, including children.
If you have questions about this policy, contact peter.greis@freethinker.com.
Effective date: 2 July 2026
Swiss Vario is an iOS app for paraglider, hang glider, and other free-flight pilots. It provides a barometric variometer, live GPS tracking, airspace overlays, live-traffic display, and an Apple Watch companion. Previously published as LiveTrack24Lite and LiveTrack 24.
Nothing on our own servers.
freethinker AG runs no server for this app. There are no analytics SDKs, no advertising SDKs, and no crash-reporting SDKs enabled in the release build. The app assigns no user identifiers of its own; any account credentials used for live tracking are ones you explicitly configure for third-party services.
Swiss Vario transmits data only to third-party services you explicitly configure and enable. Neither the app nor its developer receives any of it.
- Live tracking — while the Tracker switch is ON and a service is selected, the app periodically transmits your current GPS latitude/longitude, altitude, ground speed, heading, and vertical speed to the tracking service you chose (LiveTrack24, Skylines, or Loctome). Your account username and password for that service are included for authentication. Traffic uses HTTPS.
- Post-flight IGC upload — only when you tap "Upload Track". The recorded flight (GPS track, altitude, timestamps, and metadata such as glider model) is sent to the destination you choose (Leonardo / OLC, XContest, or Highcloud). Your credentials for that destination are included. Traffic uses HTTPS.
- Airspace file downloads from
soaringweb.org— public OpenAir airspace files. No personal information is transmitted. - Live traffic (Open Glider Network) — the app connects to OGN's public APRS relay (
aprs.glidernet.org:14580) to receive nearby aircraft positions. It does not transmit your identity or location to OGN; it sends only a standard read-only APRS login. - App-store and OS-level connections (crash logs to Apple, network reachability probes, Apple Maps tiles) are governed by Apple's own privacy policy, not this one.
On your device, in the app's sandbox:
- Recorded flight tracks (GPS logs, timestamps, altitude) are stored in a local SQLite database on your iPhone. They leave the device only if you explicitly upload them.
- Settings — tracker service selection, credentials, glider information, vario preferences — are stored in
NSUserDefaultson your device. Passwords are stored locally to enable live-tracking authentication.
Once data reaches a third-party service (LiveTrack24, Skylines, Loctome, Leonardo/OLC, XContest, Highcloud, or OGN), that service's own privacy policy governs it.
Swiss Vario requests the following iOS/watchOS permissions. Each triggers the standard OS permission prompt with a usage-string describing why:
- Location Services — required. Used for GPS tracking, map centering, and live-tracking transmissions.
- Motion & Fitness — required. Used for the barometric variometer (altitude and climb rate).
- Bluetooth — optional. Used only when you choose to connect to an external variometer (Naviter Oudie N / Omni, BlueFlyVario, XC Tracer, FlyBeeper mini BT, Stodeus BlueBip / UltraBip).
- Camera — optional. Used only when you scan a SeeYou / XCTrack task QR code. Camera frames are not stored or transmitted.
- HealthKit (Apple Watch companion only) — used solely to start a workout session that keeps the Watch app alive during a flight. No health data is read from or written to HealthKit.
Swiss Vario is not directed at children under 13 and does not knowingly collect any data from anyone, including children.
If you have questions about this policy, contact peter.greis@freethinker.com.
If we update this policy we will revise the "Effective date" above. The full revision history is visible in this repository's git log.