LodestarPrivacy Policy
Effective October 27, 2026
The short version: Lodestar processes your health data on your iPhone. We don’t run servers that receive, store or process it, we don’t sell it, and we don’t use it for advertising. The only thing the app ever sends us is feedback you choose to write.
Who we are
Lodestar is an iPhone app made by Will Barry (“we”, “us”). You can reach us at lodestar.will@gmail.com.
Data we access
With your permission, through Google sign-in, Lodestar reads the following from your Google Health account (data recorded by your Fitbit device), with read-only access:
- Activity and fitness: steps, workouts (exercise sessions), calories burned (total and active) and cardio fitness (VO₂ max).
- Health metrics and measurements: heart rate (including minute-by-minute readings), resting heart rate, heart rate variability, breathing rate, blood oxygen (SpO₂) and skin temperature.
- Sleep: sleep sessions, sleep stages and naps.
- Profile: your age, used to estimate heart-rate zones and sleep targets.
Lodestar cannot change, add to or delete anything in your Google Health account.
How we use it
Lodestar uses this data only to show you features in the app: daily scores (Energy, Sleep, Recovery, Effort, Stress), charts and trends, your personal baselines, sleep planning, alerts, widgets and notifications you turn on. All calculations happen on your device. Optional AI-written insights and Lodestar chat answers are produced by Apple’s on-device language model on your iPhone; your data is not sent to any AI service and is never used to train AI models.
Where it’s stored
Your health data and scores are stored only on your iPhone, inside the app’s private storage (and, for home-screen widgets, a small summary shared with Lodestar’s own widget on the same device). Your Google sign-in token is stored in the iOS Keychain. We have no copy. If your iPhone is backed up to iCloud or a computer, the app’s data may be included in that backup under your own account, as with any app.
How it’s protected
Every request to Google’s APIs goes over encrypted connections (HTTPS/TLS). On your iPhone, your data is kept in the app’s private storage, encrypted at rest by iOS Data Protection and unreadable by other apps. Your Google sign-in token is stored in the iOS Keychain. No server of ours receives or holds your Google data.
How long we keep it
Your data is kept only on your iPhone, until you delete it in Settings › Your Data, sign out, or delete the app. Daily summaries and scores stay until then so your history and trends keep working; minute-by-minute heart rate and steps are kept for the most recent 30 days only. We retain nothing ourselves. If you revoke Lodestar’s access in your Google Account, it stops reading your data entirely.
What we share
Nothing. We do not sell, rent, share or transfer your data to anyone, including advertisers, data brokers or AI companies. We do not use it to train AI models. Lodestar contains no advertising, analytics or tracking software.
Google API Services User Data Policy
Lodestar’s use and transfer of information received from Google APIs adheres to the Google API Services User Data Policy, including the Limited Use requirements. Specifically, data from Google Health is used only to provide user-facing features within Lodestar; it is not transferred to others, used for advertising, or read by humans, and it is processed only on your device.
Purchases
If you buy a founding membership, the purchase is handled entirely by Apple through the App Store. We never see your payment details. Apple tells the app only whether the purchase is active.
Feedback you send
If you use “Message Will, the Founder” in the app, Lodestar sends only what you type, an email address if you choose to add one, and the app and iOS version numbers. It goes to a small Lodestar service hosted by Cloudflare, which emails it to us and does not store it. Your health data is never included unless you type it yourself. To prevent abuse, the service briefly uses your IP address to limit how many notes can be sent in a short time; it is not stored or used for anything else.
If you email us directly, we receive your email address and whatever you write. Either way, we use it only to read and reply to your feedback, and we don’t add you to any mailing list.
Your choices and deleting your data
- Export: Settings › Your Data › Export All Data saves everything Lodestar holds as a file you control.
- Delete: Settings › Your Data › Delete All Data on This Phone erases all stored data and signs you out. Deleting the app also removes it.
- Revoke access: remove Lodestar from your Google Account at myaccount.google.com/permissions at any time.
Children
Lodestar is not intended for children under 13, and we don’t knowingly process children’s data.
Changes
If this policy changes, we’ll update this page and the date above. Significant changes will also be shown in the app.