Covert Mail: Morse & Ciphers

Learn Morse code the way radio operators do, crack the ciphers people really used, then send a coded message of your own.

Covert Mail is a field desk of secret codes. Each code is a dossier: read its history, practice it a few characters at a time, then decode a real message to file it in your archive.

MORSE CODE, BY EAR
• The Koch method: every character at full speed from the first lesson, two at a time, so you hear each one as a single sound instead of counting dots
• Farnsworth spacing: characters at your chosen speed with extra room between them while you learn
• Tones made on your phone at any speed and pitch, with an on-screen signal lamp and optional vibration
• Decode SOS and Samuel Morse's first message, "What hath God wrought"

SEND IT ON A BRASS KEY
Hold the on-screen key to send. Keying missions teach every letter from A to Z, and the results show your marks against the ideal timing, so you can see where your rhythm drifted. The last one has you key the Titanic's call: "Come at once. We have struck a berg."

Covert Mail first came to the App Store in 2009. This is the rebuilt version.