Signal Light

Note: Your device must have a flash to use this app!

Camper, Sailor, Soldier, Spy

A handy tool for campers, scouts, boaters, (and yes, spies)!

Use it to communicate with distant friends using Morse code, tap out a beat for a human-powered strobe light, or get the attention of rescuers.


This app is based on the old mechanical “signal lamp” which is a manually-controled shuttered spotlight used on warships to communicate securely while maintaining radio silence.

Modern navies still use signal lamps, but now use infrared wavelengths and night vision goggles!

Extra fun:

Put a paper towel tube on the flash to make a tight spotlight and you’ve got a line-of-sight communication tool that only you and your partner can see.

p.s. SOS is . . . – – – . . .