GPS speedometer · Apple Watch
Your speedat a glance
eSpeed shows your current speed on a single dial. It works on a bike, in a car, on a train or in a plane. Raise your wrist and the reading is already there. There is no sign-in or setup, and nothing is recorded.
Drag the rail Bring it to a stop and the dial pauses automatically
The dial, in parts
What the dial shows
Each panel below runs the app's own interface on this page. If you change the unit here, the watch above changes too.
Colour shows speed
Each speed has a fixed colour, running from blue to red across 0 to 350 km/h. Forty looks the same blue on a bicycle as it does in slow traffic. After about a week you can read the dial without reading the number. Above 350 km/h the colours stretch across the full 0 to 999 range. This leaves room for the colour to keep changing in a plane.
The dial zooms
The top of the scale follows your recent peak speed. Walking pace fills as much of the arc as motorway speed does. When you slow down, the scale shrinks back.
Rolling averages
A single bad satellite fix can look like a sudden burst of speed. The 5, 10 and 30 second averages under the dial smooth these out.
Signal, height, heading
The first chip shows horizontal accuracy. It turns from green to red as the GPS fix gets worse. The other two show altitude and compass heading from the same reading.
Four units
Choose kilometres per hour, metres per second, knots or miles per hour. The app keeps your choice between sessions. It is the only thing eSpeed saves.
Maximum speed
The highest speed of the session stays on screen. A bad GPS spike can leave it too high. Press and hold it to reset it. This also works in the demo here.
Limitations
What eSpeed can't do
It only runs in the foreground
eSpeed doesn't start a workout session. watchOS suspends the app and stops location updates shortly after the screen sleeps or you lower your wrist. For a continuous reading, keep the display awake with Always On, or mount the watch where you can see it.
GPS lags and can be wrong
The speed comes from satellite fixes. It settles a second or two behind your actual speed and needs a clear view of the sky. Tunnels, tall buildings and aircraft cabins all reduce its accuracy. When the fix is poor, the app tells you.
It isn't a certified instrument
eSpeed is not calibrated or certified. Don't use it where you need an accurate or legally recognised speed.
Privacy
Privacy policy
espeed.terminalvelocity.co.nz/#privacy
No data collected
eSpeed has no accounts, sign-in, analytics, advertising, third-party SDKs or servers. It does not collect personal information, usage data, identifiers or diagnostics. None of this is stored off your device or shared with anyone, including us. The app makes no network requests.
Location stays on your watch
With your permission, eSpeed reads your location from Apple's Core Location while the app is open. It uses the location only to work out the speed, acceleration, altitude and heading shown on screen. Readings are kept in memory for about 30 seconds to calculate the rolling averages. They are then discarded. Nothing is written to storage or transmitted.
What is saved
eSpeed stores your chosen unit (km/h, m/s, kn or mph) on the watch. The app opens with the unit you last used. Nothing else is saved.
Location permission
eSpeed only asks for location access while you are using the app. You can withdraw it at any time in Settings → Privacy & Security → Location Services → eSpeed. Without it, the app can't show a speed. Deleting the app also deletes the saved unit.
Your responsibility
eSpeed is an informational display. It is not a safety device, navigation aid or certified speedometer. GPS can be inaccurate, delayed or unavailable. watchOS can also suspend the app without warning. The reading may be wrong, out of date or missing at any moment.
You are responsible for your own safety and for obeying the speed limits and laws that apply to you. Do not depend on eSpeed for legal speed compliance, for navigation, or in any situation where an incorrect or missing reading could cause harm or loss. Keep your attention on the road, the water or the track. Never operate a vehicle while looking at your watch. eSpeed is provided as-is, without warranty of any kind.
Changes and contact
If this policy changes, the updated version will be published on this page. For questions about privacy or the app, email apps@terminalvelocity.co.nz.
Last updated 1 October 2026 · Terminal Velocity, New Zealand