Privacy Policy

Joule for iPhone and iPad. Last updated 6 November 2026.

Joule has no accounts, no ads and no tracking. It talks to your power station over Bluetooth and keeps what it learns on your device. Only if you agree, it sends the developer anonymous diagnostics about how your station behaves.

What stays on your device

• The station you connected, and the name you gave it.
• Up to 7 days of history: battery level and power in and out.
• Your choices in Joule, such as the answer about diagnostics.
• An activity log of what Joule and the station said to each other, the last 2,000 entries. You can read it, clear it and export it yourself in Settings › Diagnostics.

None of this leaves your device unless you export it or turn on diagnostics. Deleting Joule deletes all of it.

Bluetooth

Joule uses Bluetooth only to find your power station and talk to it. It doesn't use Bluetooth to work out where you are, and it doesn't collect anything about other devices nearby.

Diagnostics, only if you agree

Joule was built on one FOSSiBOT F1200. Other models work alike but not the same, and diagnostics show the developer how yours differs. Joule asks once, when a real station first connects. Until you say yes, nothing is sent, and you can change your answer at any time in Settings › Diagnostics. The demo station never sends anything.

With sharing on, Joule sends:

• the station's model, battery, firmware versions and limits;
• its settings and readings, as the raw numbers it reports, with the serial number removed;
• what Joule asked the station to change, and whether it did;
• fault codes the station reports;
• how the Bluetooth link behaved: how long it lasted, how quickly the station answered;
• with each of these: a random ID made for diagnostics, the version of Joule, your device's model and iOS version, your language and region settings, your time zone's offset, and the time.

The random ID is not an advertising identifier and is not linked to you, your Apple Account or your other apps. Reinstalling Joule makes a new one.

Joule never sends the station's serial number or Bluetooth address, the name you gave the station, your name, email or Apple Account, or your location.

Problem reports

With sharing on, you can send a report from Settings › Diagnostics › Report a Problem. It carries the note you write (up to 250 characters), the model you name and the station's readings at that moment. Please leave your name, email and anything else about you out of the note.

Where diagnostics go

To a server the developer runs on Cloudflare, and nowhere else: no advertisers, no analytics companies. The data is used only to make Joule work with more power stations. It is never sold, shared or combined with other data. It is deleted after 400 days.

The server looks at your IP address only to stop one address from sending too many requests in a minute. It never stores the address and doesn't work out your location from it.

Turning sharing off deletes anything still waiting on your device and stops the sending. What was already sent isn't linked to you; to have it removed, send the developer the Diagnostics ID shown in Settings › Diagnostics.

Purchases

Joule Pro is bought through Apple's App Store. Apple handles the payment, and the developer never sees your name or payment details. Joule asks the App Store, on your device, whether Joule Pro is yours.

Siri and Shortcuts

Requests you make through Siri or Shortcuts are handled by Apple under its own privacy policy. Joule carries them out on your device, over Bluetooth.

Children

Joule isn't directed at children and collects no personal information from anyone.

This website

joule.brazh.me counts visits with Cloudflare Web Analytics, which uses no cookies and doesn't follow you across sites.

Changes and contact

If Joule starts keeping or sending anything else, this page changes first, with a new date at the top. Questions and requests about your data go to the developer, Alex Brazh, through alex.brazh.me.