Live
0 Hz
Fifty samples a second from the watch or the iPhone. A trailing arc so a hit doesn’t vanish before you look.
New in version 1.9
Watch G
Feel every g.
Live g-force on Apple Watch and iPhone. Record, graph, explore.
Scroll
Green is load. Red is airtime. Zero is standing still. Watch G measures it on your wrist. G-Force Lab turns the trace into a story.
How it works
-
01
Open both apps.
Watch G on the Apple Watch. G-Force Lab on iPhone or iPad. The watch opens on the gauge.
-
02
Record on the watch.
Tap Record, do the jump, the corner, the landing. A watch recording stops by itself after five minutes.
-
03
It arrives on the iPhone.
With Auto-send on, the finished recording appears in Sessions within a few seconds.
-
04
See what happened.
The graph, the timeline, and a plain line: walking, three jumps, came to rest. Replay it in slow motion.
Watch
Thirty seconds
on a live gauge.
Stream from the watch or this device. The last ten seconds, the vector, and what it looks like right now.
The reading
Green down. Red light.
An accelerometer feels gravity and motion together. Standing still it measures 1 g. The apps show the excess: how much more or less than that you feel.
0 g
At rest. Just gravity.
Load
Pressed harder. Landing, a corner, a footstrike.
Airtime
Lighter than normal. The top of a jump. −1 g is free fall.
MAX
The strongest reading since you last pressed Reset.
Watch recording
5 min
Peak haptics, optional X Y Z axes, auto-send to iPhone.
iPhone recording
10 min
All three axes, every time. Jump, fall, drop, and impact as they happen.
On your devices
0 cloud
No account. No analytics. The apps talk over WatchConnectivity.
Version 1.9
Watch G, and the lab around it.
The session
What happened,
in order.
A plain story — “Walking 9.3 s → 3 jumps → Came to rest” — then the graph, the timeline, and the numbers. Jump height when the airtime is clean enough to measure.
Explore
What is a g?
A ladder from free fall to a fighter-jet turn. Jump height from airtime. Your best session on the same scale.
iPad
The same lab,
more room.
Gauge, chart, and vector side by side. Sessions and Explore scale to the larger screen.
Recording unlock
Free for 24 hours.
Then forever, once.
The live gauge, motion detection, and your saved sessions stay free. Recording on Apple Watch, iPhone, and iPad is free for a day. After that, unlock it for a one-time purchase. No subscription.
Trial
24 hours
Record on watch, iPhone, and iPad from the first launch of this version.
Unlock
$3.99
One-time. Buy on iPhone; it unlocks the paired watch too. Restore anytime.
Always free
Live
The gauge, detection, Explore, and every session you already saved.
Before you start
Seven steps
on the wrist.
Snug watch. All axes on. Then record.
- 01Open Watch G on the Apple Watch and G-Force Lab on the iPhone.
- 02On the watch, open Settings and turn on All axes before you record.
- 03Tap Record, do the activity, tap Stop. Five minutes is the watch limit.
- 04The file appears in Sessions on the iPhone when Auto-send is on.
- 05Open the session. Read What happened, then the graph and Timeline.
- 06In Replay, tap Play. Use ¼× to see a jump or a spike in slow motion.
- 07Share JSON or CSV from the session if you want the data in other tools.
A reading, not a medical device.
Watch G and G-Force Lab do not call for help after a fall. The watch measures your wrist, not the centre of your body. Treat every event as an estimate.
Limits
- Wear the watch snugly. A loose watch rattles.
- Arm swing shows up in every wrist reading.
- Watch recordings: 5 minutes. iPhone: 10 minutes.
- Keep Watch G open to stream live.
- Nothing is written to the Health app.
Privacy
Recordings stay on your devices. No account. No analytics SDK. Purchases go through your Apple Account.
Watch G and G-Force Lab are provided “as is” without warranties of any kind. For informational and educational use only.