Tachys Privacy Policy

Last updated: July 11, 2026

Overview

Tachys (the “App”) is a GPS speedometer for iPhone and Apple Watch developed by Code and Live. It is designed to work locally without an account or a developer-operated backend.

Code and Live does not automatically receive, collect, sell, or use your location, trip history, motion data, or app preferences for advertising, analytics, profiling, or cross-app tracking. The App nevertheless processes sensitive information, including precise location, on your devices to provide its features. This policy explains that local processing and the limited cases in which data can leave the App at your direction or through Apple platform services.

Data Processed on Your Devices

Location and trip data

While measuring speed, Tachys processes Core Location data such as precise coordinates, GPS speed, accuracy, timestamps, and GPS altitude. It derives filtered speed, maximum and average speed, distance, elapsed and moving time, route samples, signal state, transport context, and target-speed achievements.

Completed trip history is stored locally on the iPhone in the App’s shared system container. A short-lived recovery checkpoint protects an active trip if the process is interrupted. A checkpoint that is more than 48 hours old is rejected and removed when Tachys next attempts to load it.

If you keep an active measurement running, iOS may continue providing location updates in the background so that measurement and the Live Activity can continue.

Motion and altitude

Tachys uses Motion & Fitness activity classification and stillness evidence to improve stationary detection and automatic transport classification. It can use the device barometer, when available, to estimate relative altitude and vertical speed for live classification and display. Raw motion and barometer streams are not sent to Code and Live. Derived transport context and GPS altitude may be included in a saved trip.

Preferences and purchase state

Settings such as the selected speed unit, display mode, target speed, and keep-screen-awake preference are stored locally. Tachys also stores a local last-known Pro entitlement flag so purchased features remain available while offline.

Live Activity, widgets, and Apple Watch

The App, widgets, and Live Activity use Apple’s App Group storage to share only the state needed for their system surfaces, such as current speed, transport context, signal state, and a summary of the last trip.

The Apple Watch app can measure independently. A completed Watch trip, including its timestamps, speed and route samples, altitude, transport context, and trip statistics, is stored on the Watch and transferred to the paired iPhone using Apple WatchConnectivity. The Watch keeps its local transfer file until the iPhone confirms a successful import. Code and Live has no server in this transfer path and cannot access it.

You can choose to export or share trip information:

GPX exports contain precise coordinates, timestamps, and available GPS altitude.
CSV exports contain the speed timeline and corresponding coordinates and altitude.
Share cards contain selected trip statistics and do not contain the route.

These exports leave Tachys only after you use the system share sheet. The app or service you select then handles the shared copy under its own privacy policy. Copies saved or shared outside Tachys are not removed when you delete the trip in Tachys.

TestFlight and Development Diagnostics

Public App Store builds do not enable the precise field-diagnostics trace. Development and TestFlight builds can keep a bounded diagnostic buffer in memory while measuring. It can include precise coordinates, raw and filtered speed, accuracy, altitude, timestamps, signal and transport state, quality decisions, and motion stillness evidence.

Nothing is uploaded automatically. A file is created only when you explicitly choose Export diagnostic JSON in Settings. If you then send that file to Code and Live, it is used only to investigate the issue for which you shared it and is ordinarily deleted when the investigation ends, no later than 90 days after receipt unless a longer period is required for security or legal reasons.

Apple Services and Network Access

Tachys has no developer-operated API, account service, advertising SDK, or analytics SDK. Apple platform services can still communicate with Apple as part of normal operation:

StoreKit handles the Tachys Pro purchase and restoration. Tachys receives verified product and entitlement status but does not receive your payment-card details or Apple Account credentials.
Apple Maps can download map content for trip views.
Core Location, ActivityKit, WidgetKit, WatchConnectivity, the App Store, and TestFlight operate as Apple system services.
Your operating-system or device-backup settings may include App data in an Apple-managed backup.

Apple’s processing is governed by Apple’s Privacy Policy.

Data Retention and Deletion

Trip history remains on the iPhone until you delete an individual trip, choose Delete all trips, remove the App, or erase its data through the operating system. The active trip is separate from completed history, so deleting all completed trips does not end a measurement already in progress.

After a trip is archived or deleted, Tachys can retain a local one-way-derived trip identifier. It contains no route, speed samples, or coordinates and is used only to prevent a delayed Watch transfer or stale recovery checkpoint from recreating a duplicate or deliberately deleted trip. These identifiers are not sent to Code and Live and remain until the App’s local container is removed.

A pending Watch transfer can remain on the Watch until the paired iPhone acknowledges it. App preferences and the local Pro flag remain until changed or the App’s data is removed. Apple purchase records and backups are controlled by Apple. Data exported to another app or service must be deleted there.

Because Code and Live does not hold a server-side copy of your App data, it cannot retrieve or delete that local data for you. You can manage it in Tachys, in system settings, or by removing the App.

Permissions and Your Choices

Location and Precise Location: required for accurate speed, routes, and signal-loss handling. An active measurement can continue in the background.
Motion & Fitness: improves stillness and transport detection. Core GPS speed remains available with reduced context quality if you deny it.
Barometer: used only when the hardware is available and does not require a separate Tachys account.

You can change permissions at any time in iOS or watchOS Settings. Disabling a permission can limit the related features.

Children’s Privacy

Tachys is not designed specifically for children and does not knowingly collect children’s personal data on Code and Live servers. A parent or guardian can revoke sensor permissions, delete local trips, or remove the App.

Changes to This Policy

This policy may be updated as Tachys changes. The revision date at the top will identify the latest version.

Contact

For privacy questions or requests, contact Code and Live at hello@codeandlive.cz.

Website: https://codeandlive.cz

Back to Tachys