AVsync · iOS

Privacy policy

Updated: 31 October 2026 · App 2.0.5

AVsync measures audio/video offset and generates test signals. Camera and microphone data are processed on your device; the app does not upload them to the developer.

1. Developer and contact

AVsync is provided by Adrian Hilber (GitHub: LeeO86). Contact and support: GitHub profile and repository support. GitHub issues are public. Do not post personal or confidential information there. The app has no user accounts.

2. Camera, microphone and calibration

With your iOS permission, the app uses picture and sound to recognize test patterns, timecode and chirps locally. Live analysis buffers data in memory. Calibration saves short audio recordings and individual images in the app’s temporary directory so you can compare picture and sound. These files are not uploaded. They currently have no fixed automatic deletion period; iOS may purge temporary files. Clearing calibration in Settings removes the saved correction, but does not specifically delete those temporary recordings.

3. Data stored on the device

• Settings, calibration and measurements: the correction, saved date, operating system version, saved results and generator settings remain in app storage until you change or clear them, or delete the app and its data.
• Generator image: the iOS system picker provides only the image you select. The app stores a reduced copy, at most 512 pixels on its longest side, in its private directory. Replacing or removing it deletes that app-owned copy. Your original in Photos is unchanged.
• Local diagnostics: a cache file holds up to 120 recent status/measurement reports with technical detection and timing information, not camera images or audio recordings. It is not automatically transmitted. New entries replace older ones, and iOS may purge the cache.

Depending on your Apple device and backup settings, local settings and app files may be included in a device backup. Results you export and any separately saved copies are outside the app’s control.

4. Optional clock synchronization

In mobile 2.0.5, choosing the clock check on iOS sends up to four NTP (UDP) requests to the server you select; the default is time.cloudflare.com. That server receives your IP address and technical timing packets. Recordings, measurement results, generator images and labels are not sent. The developer does not control third-party server logging or retention. The earlier mobile 2.0.0 build uses up to three HTTPS requests to worldtime.timezone.io for a coarse clock check instead.

On Android, the optional GNSS time check requires precise location permission and briefly activates the GPS receiver to obtain clock measurements. The app does not read, store or upload geographic coordinates. GNSS callbacks/location updates stop after the check, on timeout or when the app enters the background. No network time request is substituted silently. Clock reference, uncertainty, correction and configured server are retained with results you save/export; references are not reused after restarting the app. Clock checks are optional and do not change the device system clock.

5. Sharing and visible test signals

Results leave the app only when you use the share sheet and choose a destination yourself; that destination’s privacy rules also apply. Generator names, subtitles and images appear on the display, where cameras or viewers may record them. QR codes and audio chirps contain technical test-signal and timing information. Only display content you intend others to see.

6. No in-app advertising or developer usage analytics

The app has no advertising networks, developer-operated usage analytics or cross-app tracking, and requires no sign-in. Apple may process crash, installation or testing information through TestFlight or enabled system diagnostics and make it available to the developer. These are governed by Apple’s privacy information and your Apple settings.

7. Permissions and deletion

You can revoke camera and microphone permissions in iOS Settings at any time. App Settings can clear saved results and calibration; the generator can remove its selected image. To remove all local app data including temporary files, use “Delete App”, rather than “Offload App”. This does not remove previously exported data, device backups or original Photos images. Contact the developer using the links above for privacy questions or concerns about your data in support interactions. Do not post sensitive information publicly.

8. Website and self-hosted MXL containers

This static website has no site-operated analytics scripts, advertising pixels or cookies. Images are hosted locally and fonts use your system. GitHub Pages hosts it; GitHub logs visitor IP addresses for security. See the GitHub Privacy Statement.

Self-hosted MXL containers carry test signals and analysis results within the media environment you configure and expose status, metrics and a web UI. Their operator is responsible for logs, network access and retention. They do not send automatic developer telemetry. This policy describes the iOS app, the Android timing module and this website; changes to data flows will be documented here.