Privacy Policy

Introduction

BayBound is built so that your commute stays yours. The app works without an account, keeps your home, workplace and location on your device, and contains no advertising, analytics or tracking. This policy explains what the app handles and where that data goes. It covers BayBound for iPhone and Apple Watch, BayBound for Android and Wear OS, and the BayBound server they talk to.

Data Stored on Your Device

BayBound stores the following on your device only:

• Your commute profile: home and work stations, commute days, the time the app switches to the trip home, and how long it takes you to reach each station
• Your home address and workplace, if you choose to enter them to estimate travel time to the station
• Reminder and location preferences, including the train you pick for the leave-by reminder
• Which departure time you usually take, scored on the device from your own app opens and rides, so the app can name your usual train. It is a time of day, never a train number, and no dates or individual rides are kept
• The Caltrain schedule and recently downloaded train status, so the app works offline
• Whether you have an active BayBound Plus subscription (a cached copy of what the App Store or Google Play reports)

If you use the watch app, your phone sends it the same commute profile over the device-to-device channel provided by the platform (Apple's WatchConnectivity, Google's Wearable Data Layer). That transfer is between your own devices and does not pass through us.

This data is never sent to us. You can erase your commute profile on the device at any time: "Erase my commute" in Settings, on either phone. Deleting the app removes everything.

Location

Location access is optional, and BayBound works fully without it.

• While using the app (optional): when "Use my location" is on, BayBound checks whether you are near one of your commute stations to show trains in the right direction, and offers the station you are standing at when you choose a station. It follows whether you have allowed location at all, so it does nothing until you have, and you can switch it off in Settings either way.
• In the background (optional): if you turn on tap reminders or the approaching-stop alert (BayBound Plus), or leave on the free ride card that starts itself when you board, BayBound asks the system to notice when you reach or leave your commute stations, so it can remind you to tap your card or phone, tell you when your stop is next, and put your ride on the lock screen as your train pulls out. This is the "Always" permission on iPhone and "Allow all the time" on Android. The app asks for it when you turn one of those reminders on, or once after a ride you tracked by hand.

Location is processed entirely on your device, by iOS or by Android. BayBound does not send your location to us or to anyone else, and does not keep a location history.

Address Search and Travel Time

If you choose to enter a home address or workplace so the app can estimate how long it takes you to reach the station, the address is handled differently on each platform:

• iPhone: the search text and the locations involved are sent to Apple's mapping service, which returns the results and the travel-time estimate. This is handled by Apple under Apple's Privacy Policy.
• Android: the search text is passed to the system geocoder, which on most devices is a Google service, so it leaves your phone and is handled by Google under Google's Privacy Policy. The travel-time estimate itself is calculated on your phone from the distance, with no request to anyone.

We do not receive the address, the search text or the result. The address you save stays on your device.

Train Data From Our Server

BayBound downloads public Caltrain schedule, delay and service alert information from our server, which gets it from 511 SF Bay Open Data, along with the current temperature at each station from the National Weather Service. These requests contain no personal information: no account, no location and no commute details. The temperatures are fetched for every station on the line, the same for everyone, so asking for them says nothing about where you are or where you are going.

The requests that register a train you are tracking (see below) additionally carry an app attestation token, issued through Firebase App Check using Apple's App Attest or Google's Play Integrity. It tells our server that the request came from a genuine, unmodified copy of BayBound on a real device, which is what keeps the push endpoints from being abused. It attests to the app, not to you: it carries no account, no location and no commute details, and we do not use it to build a profile of you. Requests that only read schedules and delays are not attested.

Like any web service, our hosting provider (Google Cloud / Firebase) automatically records standard technical request logs, which may include IP address, device type and request time. These logs are used only for security and troubleshooting and are deleted automatically, generally within 30 days.

Notifications and Live Tracking

Reminders and alerts are created on your device.

When you track a train while you ride it (a Live Activity on the iPhone Lock Screen, a Live Update in the Android notification shade), your phone gives BayBound a push token for it, which lets our server update it with delays while the app is closed. We store that token together with the train number, its date, your two stations and your door-to-platform time, and nothing else. The record is deleted automatically when the trip ends, or right away when you stop tracking. If you leave on the option to start it when you board, your phone sends the same kind of information to begin tracking when you leave your station on a train. Updates are delivered by Apple Push Notification service on iPhone and Firebase Cloud Messaging on Android.

Purchases

BayBound Plus subscriptions and tips are processed by Apple through the App Store and by Google through Google Play. We do not receive your name, email, payment details, Apple Account or Google Account. The app checks your subscription status with the store on your device.

No Analytics, Advertising or Tracking

BayBound does not use analytics or crash-reporting services, does not show ads, does not use advertising identifiers (Apple's IDFA or the Android advertising ID), and does not track you across apps or websites. We do not sell or share personal information, because we do not collect it.

Children's Privacy

BayBound is designed for general audiences and is not directed to children under 13. We do not knowingly collect personal information from children.

Changes to This Privacy Policy

If a future feature changes what BayBound collects, we will update this policy before releasing it and post the new effective date here.

Contact Us

For questions about this Privacy Policy or our data practices, please contact us through the Contact page.

Effective date: October 15, 2026. Previous versions: October 14, 2026, October 13, 2026, September 21, 2026 and September 19, 2026.

BayBound is an unofficial app and is not affiliated with or endorsed by Caltrain. Transit data provided by 511.org.