Privacy Policy

Companion: Diabetes Journal · Effective October 12, 2026

Companion is made by Vishnu Purushothaman, an independent developer. It is built so that your health information stays with you. There is no Companion account and no Companion server, and nothing you log is sent to us. This page says exactly what the app stores, what leaves your device, who receives it, and how to delete it.

What the app stores

Everything you enter is stored on your iPhone in the app's own database: glucose readings, meals and foods (with any photo you attach to a meal), activity, medications and doses (including injection sites and any reason you note for a skipped dose), lab results such as A1C, supplies and checkup dates, your sick-day plan, questions for your doctor, today's Ask Companion conversation, your name and diabetes type if you give them, and your preferences.

A small summary (today's readings, the carb total and the time of the next dose, never food or medication names) is shared with Companion's widgets and, if you have one, your paired Apple Watch, so they can show it. A reading you log on the watch is sent to your iPhone over Apple's WatchConnectivity.

Companion does not sync the journal to iCloud or to any server. Like every app's data, it is included in your iPhone's own backups if you make them (iCloud Backup, or a backup on your computer), and in any CSV export you make yourself.

What leaves your device

Apple Health

With your permission, Companion reads the Health categories you choose: blood glucose, steps, walking and running distance, exercise minutes, workouts, State of Mind, and (on iOS 26) the medications you choose to share and their doses. If you allow it, it writes the glucose readings and meals (carbohydrate, protein, fat, fiber, sugar and calories) you log back to Health. Health data is used only to show your own journal to you. It is never used for advertising or marketing, never sold, and never sent to us or to any third party, and not synced to iCloud by Companion. You can change access at any time in the Health app under Sharing.

Third parties

Companion contains no third-party analytics, advertising, or tracking code, and it does not track you across apps or websites. The only outside service that receives anything from the current version is Open Food Facts (a barcode number), as described above; it handles that request under its own privacy policy, linked above. We do not share, sell, or rent your data to anyone.

Analytics

Companion may note on the device that a feature was used, for example "a meal was logged". It never records what you logged. These notes stay on the device and are not transmitted.

Purchases

Companion Plus is sold through Apple. Apple handles payment and shares no payment details with us. Your subscription status is checked on your device.

Keeping and deleting your data

Your journal is kept until you delete it. You can change or delete any entry from the entry itself. Delete all data in Profile removes everything you logged and wrote down, including your Ask conversation, your sick-day plan and the contacts you saved, from the device. Your name and preferences stay until you delete the app. Deleting the app removes all of its data from the device. Data you allowed Companion to write to Apple Health stays in Health until you delete it there. Because we hold no copy of your journal, there is nothing for us to delete on our side; if you email us, we will delete your email on request.

To withdraw a permission at any time: Apple Health access in the Health app (Sharing → Apps → Companion), notifications, camera, microphone and speech recognition in the Settings app. Export everything as CSV from Profile whenever you like.

Children

Companion does not collect personal information from anyone, including children. A parent or guardian who sets it up for a child can delete everything as described above.

Not medical advice

Companion organizes information you provide. It does not diagnose, prescribe, calculate doses, or replace advice from your healthcare team. Check with your doctor before making medical decisions.

Contact

Questions about privacy: vishnusaip25@gmail.com. See also the support page.

Changes to this policy will be posted on this page with a new effective date.