Privacy policy
Last updated July 30, 2026
Treadwell measures your treadmill's real belt speed using your iPhone's camera and LiDAR sensor. This policy explains what the app collects, what it doesn't, and what happens to your data. The short version: almost everything stays on your phone.
What stays on your phone
- The measurement itself. The app uses your camera and LiDAR sensor to watch the belt and calculate its speed. That video and the calculation happen on your phone. They are not uploaded anywhere by default.
- Your calibrations, treadmills, runs, and settings. Calibration profiles, saved treadmills, workout and run history, and app settings are stored locally on your device. They are not sent to a server.
- An install identifier. On first launch the app generates a random identifier and stores it on your device. It is not derived from any hardware identifier and carries no personal information by itself. It exists so that, if you ever choose to send us a report, we can tell your reports apart from someone else's.
What the app does not collect
- No location data of any kind. No GPS, no network names.
- No contacts, no photo library access, no microphone recording.
- No advertising identifiers and no third-party analytics or advertising SDKs.
Purchases
The one-time Pro unlock is handled entirely by Apple's App Store. Treadwell never sees or stores your payment details; Apple processes the transaction.
If you're a beta tester (TestFlight)
TestFlight beta builds include two things the public App Store version does not:
- Opt-in problem reports. After a failed measurement, or from Settings, you can choose to send us a report. It contains a short video clip of the treadmill belt, tracking data, and device diagnostics, plus a name, email, and note if you choose to add them. It goes only to the developer's private storage, is used only to fix tracking problems, and is not shared with anyone else. Nothing is sent unless you tap the button.
- Beta usage stats. Beta builds automatically record when the app is opened and which features are used, along with the device model, iOS version, and app version, tied to the install identifier above. This helps us understand what beta testers actually use. It exists only in beta builds; the public App Store version does not include this collection.
The website
This website (treadwellapp.com), separate from the app, uses Microsoft Clarity to record anonymized page activity, such as which pages are visited and how far down them people scroll, so we can improve the site. The site does not ask you for an email address and has no signup form. If you joined our email list while Treadwell was in beta, that address is held with our email provider, MailerLite, and used only to contact you about Treadwell. None of this has anything to do with the app on your phone.
Deleting your data
Because your data lives on your device, deleting the app removes it. If you sent us a beta report or your email is on our list, contact us at support@treadwellapp.com and we'll delete what we hold.
Children
Treadwell is not intended for use by children under 13.
Changes
If a future version of the app changes what it collects, this policy will be updated before that version ships, with the date above.
Contact
Questions about this policy: support@treadwellapp.com