With the waterfall display, in addition to FFT, allow also the following things to be displayed:

• statistical distribution of the signal within the window of a single stripe of the waterfall display
• wavelet transform
• ability to display a time domain signal. For every update, the signal waits for a trigger, and then starts printing the stripe from the trigger. A v/t signal (vertical: signal voltage, horizontal: time) gets turned into a stripe where the voltage is turned into intensity, and the signal's time is along the stripe. When I say stripe, I mean the latest updated part of the waterfall display, the latest "line" or "row" that's being printed. Essentially, this would be like "analog tv mode" configuration for the scope.
• input from any math function. similar to time domain signals above.