Control the width (time) the flash light stays on, or off while sending a light message.
Send the message repeatedly by choosing the repeat feature.
Press the Pulse title row to play or stop the pulse signal.
Press the Pulse title row for more than one second to edit or delete the pulse.
Rather than have an app that just switches on your device flash light, use the flash light to send messages.
For example to repeatedly flash the light use pulse signal 101 and chose option repeat. To send the International SOS signal, use pulse signal 111000111.