Overview
Chainline (“the App”) is developed by Leilei Zhang. It is an offline bike maintenance log that tracks wear on your chain, tyres, brake pads and other parts. This page explains what the App does — and does not — do with your data.
Short version: Chainline collects no data. Your bikes, parts, rides and service records are stored only on your device. There is no account, no server and no database.
Apple Health
If you allow it, Chainline reads your cycling workouts from Apple Health so their distance can be added to your bike. This access is optional, read-only and can be turned off at any time in the Health app (Profile → Apps → Chainline).
- Chainline never writes to Apple Health.
- Health data is used only on your device to update your bike’s distance. It is never sent anywhere, shared with third parties, or used for advertising or marketing.
What We Do NOT Collect
- We do not collect your name, location, or contact information
- We do not track your usage or behavior
- We do not use advertising networks or analytics SDKs
- We do not send any bike, ride, service or health data off your device
- We do not require an account or login
Data Storage
Everything you enter or import is stored locally on your device using Apple’s SwiftData framework. Nothing is synced to any server. Your data is included in your normal iPhone backup (iCloud or computer backup), so it comes back if you restore your device.
CSV exports and backup files are created only when you ask for them, and you choose where to save or share them.
Purchases
The one-time “Chainline Pro” purchase is processed by Apple. We never see your payment details.
Crash Reports
If you have enabled “Share with App Developers” in iOS settings, Apple may share anonymous crash reports with us. They contain your device model, iOS version and a technical stack trace, and no personal information.
Children’s Privacy
This app is not directed at children under 13.
Changes to This Policy
We will post any changes here with an updated date.
Contact
Email: [email protected]