HALO Privacy Policy

Last updated 14 September 2026 (v0.9)

HALO is a personal weight, food and activity tracker for Android. This policy explains what data HALO handles and where it goes.

Data stored on your phone

Your profile, food diary, weigh-ins, water, workouts, steps, body measurements, progress photos, reminders and achievements are stored in HALO's private storage on your phone. HALO has no user accounts. Your data leaves the phone only as described below, for example as encrypted backups if you turn HALO Cloud on.

Health Connect

If you connect Health Connect, HALO reads the data types you approve:

If you turn on sharing, HALO writes the food and weigh-ins you log in HALO to Health Connect. Data read from Health Connect is never sent off your phone, never used for advertising, and never shared with third parties. You can revoke access at any time in Health Connect settings. HALO's use of Health Connect data follows the Health Connect Permissions policy, including the Limited Use requirements.

Food lookups

When you search for packaged foods or scan a barcode, the search words or barcode number are sent to halo.proxlabs.net, which keeps a weekly copy of Australian products from Open Food Facts. If the product isn't found there, or the server can't be reached, the search words or barcode are sent to Open Food Facts instead. Nothing that identifies you is included, and HALO doesn't log searches or barcodes. Whole foods and dishes (FSANZ AFCD and AUSNUT 2023) and US foods (USDA FoodData Central) are searched in databases built into the app. Nutrition label scanning is processed on your phone.

Snap meal

Snap meal photos are analysed entirely on your phone. HALO includes Google's AIY food recognition model, and on phones that support it, uses Google's Gemini Nano through Android's on-device AI service (AICore). Photos are never uploaded to HALO or anyone else, and the temporary photo is deleted once you've finished. Nutrition values come from the Australian Food Composition Database built into the app.

Check-in photos

Progress photos are taken with HALO's own camera screen and kept in HALO's private storage on your phone, never in your photo gallery. HALO blocks screenshots while photos are on screen and doesn't use them for any AI feature. With app lock on, they stay hidden until you unlock with your fingerprint, face or screen lock. HALO doesn't use Android's own device backup; photos leave your phone only in the backups described below.

Google Drive backup

If you connect Google Drive, HALO backs up to a "HALO Backup" folder in your own Google account. Your data and photos are encrypted on your phone with a key derived from your recovery code before upload, so Google can't read them. HALO requests only Google's drive.file permission, which lets it see and manage the files it creates and nothing else in your Drive. You can disconnect in Profile; existing files stay in your Drive until you delete them.

HALO Cloud backup

If you turn on cloud backup, HALO encrypts your data and each check-in photo on your phone with AES-256-GCM, using a key derived from your recovery code, and uploads only the encrypted files to halo.proxlabs.net. Each photo is uploaded once, under an identifier that can't be linked back to it. The server stores an account identifier and a hash of an access token, both derived from the recovery code, and cannot decrypt anything. The 14 most recent data backups are kept; photos you delete are removed at your next backup. Turning cloud backup off lets you delete everything from the server immediately.

Updates, crash reports and feedback

HALO checks halo.proxlabs.net for new versions and downloads updates from it. If HALO crashes, a technical report is sent to the same server containing the app version, phone model, Android version, the error and a short technical log. Feedback you choose to send includes your message and, if you tick the box, the same technical log. Reports and feedback never include your food, weight, measurements, photos or other health values. They are used only to fix and improve HALO and are deleted when no longer needed.

Backups and exports

Manual backups, automatic folder backups and spreadsheet exports are saved only to the location you pick. These aren't encrypted. The JSON export leaves out photos; "Export with photos" and folder backups include them.

Deleting your data

Profile → Reset everything erases all HALO data from your phone. Uninstalling HALO does the same. To ask for crash reports or feedback you've sent to be deleted, use Send feedback in the app.

Not medical advice

Energy budgets and targets are estimates for general wellness and are not medical advice.