Privacy policy

1. What we collect

Nothing. ChorusLink has no account system, no analytics SDK, no advertising identifiers, no ads, no crash reporter and no third-party SDKs of any kind. It never asks you for a name, an email or an age. The answer we filed with Apple on the App Store listing is "Data Not Collected", and this page is what that answer means in practice. We could not tell you who our users are, and we like it that way.

2. Nothing leaves your Mac

This is the unusual part, so it is worth being exact: the app contains no networking code at all. It opens no connections, talks to no server of ours or anyone else's, and works identically with your Mac offline. Everything below happens inside the app on your own machine, and the only reason any of it exists is to get sound out of your speakers at the right moment.

3. The audio you play

To send the same moment of music to every speaker, ChorusLink has to be holding that moment. macOS gives it the audio already playing on your Mac through a system audio tap, which is why you are asked to allow that the first time. The audio passes through the app and out to your speakers, a fraction of a second at a time, and is then gone. It is never written to disk, never kept after it has played, and never transmitted — there is nowhere for it to be transmitted to. ChorusLink does not know or care what you are listening to: it has no idea what app the sound came from, no listening history, and no interest in one.

4. The microphone, and what it is for

Bluetooth speakers each lag by a different amount, and the only way to know by how much is to measure it. So ChorusLink plays a short tick through one speaker and uses your Mac's microphone to hear when it arrives. The gap between the two is the number it needs — a few milliseconds — and that number is all it keeps.

The microphone is used for that measurement and nothing else. The recording exists only in memory for the second or two the tick takes, is used only to find the tick in it, and is discarded immediately. No audio from your microphone is saved to disk, played back, kept after a measurement, or sent anywhere. If you would rather it never ran at all, deny the microphone permission: calibration is the part that stops working, and grouping, playback and per-speaker volume carry on without it.

5. Bluetooth

ChorusLink uses Bluetooth to see the speakers your Mac is paired with and to reconnect one that has dropped, so you can get it playing again without leaving the app. It reads what your Mac already knows about your own speakers; it does not scan for other people's devices, does not use Bluetooth to work out where you are, and has nowhere to report either.

6. What stays on your Mac

Your groups, the names you gave your speakers, their volumes, and the delay measurements ChorusLink took are written as ordinary settings inside the app's own sandboxed folder on your device. They are not synced to us, because there is no us to sync to. The app is sandboxed, so it reaches nothing outside that folder except the audio devices and the microphone you allowed it.

7. What the app costs

It is free, and it has no in-app purchases, no subscription and nothing that renews. There is no transaction between you and us, so there is nothing about your payment details for us to see. If the price ever changes, Apple handles the money and sends us an anonymous sales report — never your name, your email or your card.

8. Support email

If you write to support, we keep the thread so we can help you, and we delete it after 12 months. We never add you to a mailing list without asking.

9. Who else sees any of this

Nobody. There are no analytics providers, no ad networks, no third-party SDKs and no parent or sibling company with access to anything. Apple is involved only because Apple runs the Mac App Store and the frameworks the app is built on — it never receives your audio, your measurements or your settings from us. We share your data with no one, we do not sell it, and we do not use it to train anything. If that ever changed we would only work with someone bound to protect your data at least as well as this policy does — and we would say so here before it happened, not after.

10. Keeping and deleting

We hold nothing of yours to delete, because nothing the app does ever reaches us. Your groups, speaker names and measurements stay on your Mac for as long as you keep the app; deleting the app deletes them, and there is no copy anywhere else to survive that. Support threads are the one thing we do hold, and we delete those after 12 months — or sooner, if you ask us to.

11. Taking permission back

ChorusLink asks for three things, and you can take back any of them at any time in System Settings → Privacy & Security: the microphone, under Microphone; the audio playing on your Mac, under Audio Recording; and Bluetooth, under Bluetooth. Nothing is hidden behind a permission you cannot revoke, and revoking one costs you only the feature it was for — the microphone costs you calibration, the audio permission costs you playback to the group, and Bluetooth costs you reconnecting a dropped speaker. Your groups and settings are untouched either way. There is no tracking prompt to revoke, because there is no tracking.

12. Children

The app is not directed at children and never asks anyone their age — it never asks anyone anything. We don't knowingly collect data from anybody, children included, and the app is rated 4+ because there is nothing in it to rate higher.

13. Changes

If this policy ever changes, the new version appears here with a new effective date. Given how little we collect, changes should be rare and boring.