Sam is a Morse code trainer. It is a bash script that runs in a terminal. It beeps and boops out the command-line arguments in Morse code. If there are no command-line arguments, then it beeps and boops the Usage message. Simple, no? But the gimmick is that it prints out the text to the terminal, and the cursor below the text keeps track of which letter is being sounded.
Gpredict is a real time satellite tracking and orbit prediction program. Besides the general orbital data for satellites, gpredict can also calculate the footprint, visibility, doppler shift, signal loss, and signal delay for each satellite relative to one or more ground stations. The calculated data can be viewed in tables, on maps, or on polar graphs.