BT Battery Notifier
Privacy Policy
Last updated: 28 August 2026
Summary
BT Battery Notifier has no account, no analytics, no ads, and sells nothing to anyone. By default nothing leaves your device.
The one exception is sync between your phone and your Mac, added in version 2.0. It is optional and only works after you link the two devices with a code. Until you do, the app makes no network connection at all. Once you do, what travels is encrypted end to end and is described below.
What the app reads
To do its job, the app reads the following from the device itself, locally:
- The names and hardware addresses of the Bluetooth devices you have already paired
- The battery levels those devices report
- Whether they are currently connected, and whether they are charging
- The device's own battery level
This comes from the operating system and from the Bluetooth standard (the Battery Service, plus the battery notices the system receives from the accessory). It is used only to render the device list, the menu bar, the home screen widget, and the notifications you enabled.
Where it is stored
All of it stays on the device. Your settings and the last battery reading for each device live in the app's private storage, which only the app can read. Nothing is uploaded anywhere unless you have linked your phone to your Mac — and in that case only what the section below describes leaves the device.
Phone-to-Mac sync (optional)
If you link the two apps, each one starts sending the other what only it can read. This is optional, it stays off until you link them, and you choose device by device what gets sent.
What is sent: the device name, the battery level (left, right and case included), whether it is connected, whether it is charging and how long until it is full, the time of the last reading, and the name of the device it came from — so the other side knows where the number originated.
What is not sent: nothing beyond that. No e-mail, no account, no contacts, no location, no advertising identifier, no device identifier.
How it is protected: the content is encrypted on your device with AES-256-GCM before it leaves, with a key that exists only on your two devices. That key is derived from the code you scan or type when pairing, and is never sent to any server. The relay in the middle only passes encrypted bytes along: it does not hold the key and cannot open the content.
Who can see it: nobody but your own devices. That relay is run by the app's author, keeps the last encrypted state from each side for at most 7 days, and identifies the pair by random numbers that say nothing about you. There is no sign-up, no e-mail, and no dashboard where anyone could look at your devices.
How to undo it: tap Disconnect on the My Mac screen on the phone, or Disconnect in the Phone pane of the Mac's settings. That erases the key on both devices and deletes the stored state from the relay. A pair left unused for 30 days is deleted on its own.
Permissions
On the Mac:
- Bluetooth — required to see the devices you have already paired and read their battery levels. Without it the list stays empty.
- Notifications — for the low-battery and connect/disconnect alerts.
- Network — used only by the sync described above. With no pair configured, the app makes no requests.
On Android:
- Nearby devices (
BLUETOOTH_CONNECT) — required to see the devices you have already paired and read their battery levels. The app does not scan for new devices and does not request location access. - Notifications — for the low-battery and connect/disconnect alerts.
- Vibration — used only by the low-battery alert.
- Internet — used only by the sync described above.
Permissions are requested on first use and can be revoked at any time in the system settings.
Purchases
When there is a purchase, the store handles it — Apple on the Mac App Store, Google on Google Play. Payment happens there: the app never sees or stores card details. All it receives from the store is whether that account has bought or not.
Removing your data
Uninstalling the app erases everything it stored on the device. If you had linked your phone to your Mac, tap Disconnect first — that also deletes the encrypted state held by the relay. Without doing so, that state expires on its own: each reading within 7 days, the whole pair after 30 days without use.
Children
The app does not ask for or collect personal data from anyone, including children.
Changes
If this policy changes, the updated version will be published at this same address with a new "last updated" date.