Hinge-angle measurement for foldable Android phones.
Effective date: 2026-08-30 Controller: FoldFlow Oy, Finland Contact: admin@maxwase.eu
This policy covers the Protractor Android app (“the app”). It is written to be read alongside the app’s Play Store Data Safety declaration, which summarizes the same facts in Google’s format.
Protractor reads your device’s hinge-angle sensor to display the angle between the two halves of your foldable phone. The calibration it learns (your hinge’s sensor resolution) and every angle you choose to save are stored only in the app’s local storage on your device. Neither is ever sent anywhere. Calibration is additionally excluded from Android’s automatic cloud backup, since a resolution measured on one phone would be meaningless on another; saved measurements are backed up like any other app data, so they can follow you to a new device.
If you grant consent (a separate prompt in the app, never on by default), the app sends anonymous
usage analytics through PostHog, processed exclusively in PostHog’s
EU region (eu.i.posthog.com).
What is sent: which buttons and gestures you use, which screens you visit, whether a sensor check was completed or abandoned, whether the reading moved outside the checked range, and whether your device’s hinge sensor turned out to report only a few fixed positions rather than a continuous angle. These last events contain no properties derived from sensor readings.
What is never sent: angle readings, angle ranges or bands, sensor-resolution estimates, calibration sample counts, or transitions between measured positions. The app’s analytics vocabulary has no angle-derived property and no numeric-angle property type, so these values cannot be attached to an event by mistake.
Alongside those events, the PostHog SDK attaches standard technical context to each one: your device’s manufacturer, model and form factor, Android version, the app’s version, your device’s locale and time zone, and the display language you have selected inside the app. PostHog also derives an approximate location (country, region, and city) from the IP address the event is sent from; the IP address itself is not stored as an event property. This context is what makes the events useful — knowing that a hinge sensor reports only fixed positions is only actionable if we know which phones report that way.
An anonymous identifier is generated by the PostHog SDK to distinguish one installation’s events from another’s; it is not linked to your name, email, or any other identifying information the app collects, because the app does not collect any. The technical context above describes your device and its settings, not you, and is not used to build a profile or to attempt to identify you.
If an event occurs before you have answered the consent prompt, it is held in the app’s memory until you answer. If you grant consent it is then sent; if you decline, or if you close the app first, it is discarded. Nothing is written to disk and nothing leaves your device while the prompt is unanswered, and the PostHog SDK is not started at all until you have granted consent.
Analytics is entirely optional. You can grant or withdraw consent at any time from the app’s settings menu, and withdrawing clears the locally stored anonymous identifier immediately.
The app is used by residents of the EU and elsewhere. Where GDPR applies, the legal basis for analytics processing is your consent (Article 6(1)(a)), which you can withdraw at any time as described above with no effect on the app’s core functionality. Storing or reading anything on your device for analytics purposes requires your prior opt-in under Finland’s Act on Electronic Communications Services (implementing ePrivacy Directive Art. 5(3)); the in-app consent prompt is how that opt-in is obtained, before any analytics code runs.
You have the right to access, correct, or request erasure of any data processed about you, to object to or restrict processing, and to lodge a complaint with your national data protection authority (in Finland, the Office of the Data Protection Ombudsman). Because analytics events carry only a locally generated anonymous identifier with no link to your identity, FoldFlow Oy cannot look up or delete data tied to a specific person without you providing that identifier — withdrawing consent in the app is the practical equivalent of an erasure request, since it clears the identifier being used going forward. For any request, contact admin@maxwase.eu.
Analytics events are retained in PostHog for the duration of FoldFlow Oy’s PostHog subscription’s default retention period, after which PostHog deletes them automatically. FoldFlow Oy does not separately archive or export analytics data.
Analytics data is processed by PostHog (sub-processor) under PostHog’s own EU-hosted infrastructure and data processing terms. It is never sold, and never shared for advertising purposes. No other third party receives data from this app.
If this policy changes, the “Effective date” above will be updated and, for material changes, the app will show the consent prompt again.