Tools that work in a browser — and tools that don’t
Three working demos on this site. The rest need a phone: magnetometer, torch, camera, cellular radio. We will not ship eight doorway pages that say “open the app.”
Use these here
Morse, knots, and rationing do not need a sensor the laptop lacks. Each page is a full tool plus the one worked detail that proves it, then a title index into the library.
On the phone only
These are in the app’s Tools tab. A web page cannot honestly demo them. Listing them here is the index; the working copy is on-device.
SOS Signal
Needs the rear flashlight. Open Tools in the app.
Survival Timer
On-device presets with the screen awake.
Morse Decoder
Optical receive needs the camera. Text Morse is on the translator page.
Signal Mirror
Uses the screen as a bright panel plus orientation.
Compass
Needs a magnetometer. Laptops usually don’t have one.
Clinometer
Uses the phone IMU.
Lux Meter
Samples the camera sensor.
Whistle
Loud enough to matter only on a phone speaker in the field — use a real whistle.
Signal Finder
Reads the radio you are holding. No radio in a desktop browser.
Then get it on the phone
The compass does not live in Chrome. Download the kit before you need the heading.