Privacy
Last updated 14 November 2026
In short: no account, no ads, no tracking, no analytics. Your settings stay on your device. The microphone is used only when you ask for a measurement, it is analysed on your device and never recorded or sent anywhere. If you buy Pro on the website, the app sends your license key and a rough device label (such as "Windows") to Lemon Squeezy to check it, and nothing else. In the iPhone app, Pro is bought through Apple and no license data is sent.
What stays on your device
Your sessions, favorites, recently played list, daily listening time (for the "This week" card), your last Verify results (just the measured numbers), settings, saved templates, plate and visual choices, whether you have seen the intro, the day your free Pro trial started, whether you used the app before Pro existed (early users keep Pro free) and, if you bought Pro, your license key are kept in your browser's local storage on your device. They are never uploaded. Clearing the site's data in your browser (or deleting the app) removes them. The iPhone app has no trial, early-user mark or license key to store; it keeps whether you bought Pro through Apple on your iPhone.
The app also keeps a copy of its own files on your device so it works offline. Its typefaces (Space Grotesk and JetBrains Mono, open-source) come with the app, so no font service is contacted.
Microphone
The microphone is used only when you ask the app to measure a sound with it (Listen). The sound is analysed live on your device to measure its frequency. The sound is never recorded, stored or sent anywhere; at most the resulting number (for example 432.00 Hz) is kept on your device. The mic switches off when you stop it, when you leave the measuring screen, and when the app goes to the background.
Share links
A share link carries the session's settings inside the link itself, after the #. Browsers do not send that part of a link to any server, so sharing a session uploads nothing. Anyone you send the link to can see those settings.
Buying Pro and license keys
Pro is bought on Lemon Squeezy's checkout page, which opens outside the app. Lemon Squeezy is the merchant of record: it receives your payment details, email address and billing country under its privacy policy, and sends your receipt and license key. The app never sees your card.
When you activate Pro, the app sends your license key and a rough device label (such as "iPhone/iPad" or "Windows", so each activation can be told apart) to Lemon Squeezy's license service to check that the key is real. After that, about once a week when you are online, it sends the key again to check it is still valid (for example, that it wasn't refunded). Only the key goes; nothing about what you play, your settings or your measurements.
The free trial (website only) needs no account and no payment details. It is counted on your device only.
In the iPhone app, Pro is sold through Apple's in-app purchase. Apple handles the payment, and any refund, under its own privacy policy; the app never sees your payment details and checks your purchase with Apple on your iPhone. Restore Purchases asks Apple for the purchases on your Apple Account. The app has no license key field and sends nothing to Lemon Squeezy.
In the Android app, Pro is sold through Google Play Billing. Google handles the payment, and any refund, under its own privacy policy; the app never sees your payment details and checks your purchase with Google Play on your phone. The Android app opens this website inside Chrome, so it shares Chrome's storage for frequencylab.app on that phone.
Other services the app contacts
- Netlify hosts the app. Like any web host, it receives standard request information (such as your IP address and browser type) when your device downloads the app's files. See Netlify's privacy policy.
- Apple handles buying and restoring Pro in the iPhone app (see above).
- Google Play handles buying Pro in the Android app (see above).
- Updates in the iPhone app: when it starts (at most every six hours), the app asks frequencylab.app (version 1.0: frequency-lab.netlify.app, the same site) for signed updates of its own files and uses them from the next launch. Netlify receives standard request information; nothing about you or how you use the app is sent.
- Lemon Squeezy (website only) checks your Pro license key, only when you activate it and about once a week afterwards (see above). It receives the key, the device label and standard request information.
- jsDelivr supplies the open-source Butterchurn library, only when you open the "trip" or "flow" visuals on the website (the iPhone app has its own copy). jsDelivr receives standard request information when it is downloaded. See jsDelivr's privacy policy.
Nothing you do in the app (what you play, for how long, your settings, your measurements) is sent to any of them.
Health
Frequency Lab is a sound and visual tool, not a medical device. It does not diagnose, treat or prevent anything. Where the app mentions research, it says what the research found; tuning traditions are labelled as tradition.
Changes
If this policy changes, the date at the top changes with it.
Contact
Frequency Lab is run by Michael Iwaniec, Illinois, USA, who is responsible for this app and this policy. Privacy questions: thefrequencylabofficial@gmail.com.