MorseLightCrypt

Send text as Morse code with the flashlight and read it back with the camera, optionally encrypted with a master password.

One phone flashes, another one points its camera at the light and turns the pulses back into text. It also reads any other blinking light: a lamp, a screen, a torch in the distance.

• Send: type, pick the speed, flash. Repeat in a loop so the receiver has time to get settled.
• Receive: aim and press Start. Pinch to zoom on distant lights. Each repeat lands on its own line, and the received text can be edited by hand.
• Encrypt / Decrypt: AES-256 with a master password, in a compact format of letters and digits made for Morse: "HOLA MUNDO" becomes 26 characters.

The receiver follows only what blinks, so a bright screen next to the lamp does not blind it. It measures the sender's speed by itself, tolerates a hand holding the phone and pauses while the phone moves.

No network permission: nothing leaves the phone except light. Nothing is stored.

Sending needs a phone with a flashlight; receiving needs a camera.