RunCraft Privacy Policy

Effective date: 11 June 2026 Last updated: 25 July 2026

This Privacy Policy describes how the RunCraft app (“RunCraft”, “we”, “us”) handles your data. The short version: your data stays yours — it lives on your devices and syncs only through your own private iCloud. RunCraft has no servers of its own, no accounts, no analytics, and no third-party tracking.

Who we are

RunCraft is an iOS app for serious runners following Jack Daniels’ VDOT training methodology. It is published by Cheng Lung Lin as a personal project.

Contact: support@marstudio.app

What data RunCraft reads

When you grant permission, RunCraft reads the following from Apple Health (HealthKit) on your iPhone:

Running workouts — distance, duration, start time. Used to detect a best 5K / 10K / Half Marathon time and derive your initial VDOT.
Heart Rate Variability (HRV) — last 7 days’ average. Used by the “Recovery looks low today” banner to suggest swapping a hard session for an easy run.
Sleep — last night’s total. Same purpose as HRV.
VO₂max — last 180 days of samples. Plotted on the Insights tab alongside your VDOT trend.

Reads only. RunCraft does not write anything back to HealthKit.

You can revoke this access at any time: iOS Settings → Privacy & Security → Health → RunCraft. When access is revoked, the affected features (VDOT detection, recovery banner, VO₂max chart) silently stop working but RunCraft continues to function for everything else.

What data RunCraft stores

Everything RunCraft generates is stored locally on your iPhone in a private SQLite database inside the app’s sandbox:

Your race goal (name, date, distance)
The generated 16-week training plan
Workouts you author and templates you save
Completed run records (when you log them by voice or HealthKit syncs)
VDOT history (one row per change)
Your preferences (pace unit, reminder time, etc.)

This database syncs across your own Apple devices through your private iCloud account (Apple’s CloudKit private database), so your plan and history follow you from one iPhone to the next. That sync stays entirely within your iCloud — RunCraft has no servers of its own and never receives, sees, or stores your data. You can turn the sync off in iOS Settings → [your name] → iCloud → Apps Using iCloud → RunCraft.

To delete the data: delete RunCraft from your iPhone. To remove synced copies, also turn off RunCraft in iCloud from the same Settings screen.

What Apple frameworks handle

Some features hand off to Apple’s own systems, which have their own privacy policies that apply when they receive data:

WorkoutKit — when you tap “Start Workout”, the workout structure is dispatched to your paired Apple Watch via Apple’s WorkoutScheduler. Subject to Apple’s privacy policy.
App Intents / Siri — when you ask Siri “what’s today’s training?”, the response is generated locally but the voice transcription and invocation are handled by Apple. Subject to Apple’s Siri privacy policy.
Local Notifications — daily training reminders are scheduled via UNUserNotificationCenter and delivered locally. No notification data leaves your iPhone.

RunCraft never sees your Siri transcriptions or your Apple ID.

What we don’t collect

To be explicit:

❌ No account, no sign-up, no email collection
❌ No analytics (no Firebase, no Mixpanel, no Amplitude)
❌ No crash reporting service (no Sentry, no Crashlytics)
❌ No advertising SDKs
❌ No third-party trackers
❌ No location data beyond what HealthKit workouts already contain
❌ No third-party cloud — the only sync is through your own private Apple iCloud, never our servers (we have none)

Children

RunCraft is rated 4+ on the App Store and contains no objectionable content. We do not knowingly collect data from children under 13 because we do not collect any user-identifying data, period.

Changes to this policy

If we change how RunCraft handles your data — including a future Pro subscription tier or any change to what is synced — this page will be updated and the effective date at the top will change. Material changes will be surfaced in-app via the Settings → About section so you don’t have to re-read the policy to know something has changed.

Contact

Questions, concerns, or requests: support@marstudio.app.

Last reviewed: 25 July 2026