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Signal Light app for iPhone and iPad


4.6 ( 6256 ratings )
Utilities Education
Developer: Bryan Wu
0.99 USD
Current version: 1.0.4, last update: 1 year ago
First release : 14 Nov 2015
App size: 20.84 Mb

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 . . . – – – . . .