I miss Cathode. It was a Mac application that allowed to mimic bad CRTs (cathode ray tubes). Effects included jitter, scan lines, and flicker. https://youtu.be/Q7uXxiRhpbE
the xscreensaver apple2 hack does this if invoked with -text. beware, without -fast it also simulates the apple ]['s slow text output, and it always simulates the apple ]['s lack of lowercase