This Mac application really takes me back to when tubes were hot technology. Back in the day, when I was learning programming in college, I had the patience-building experience of programming on a hard copy terminal (the DecWriter) for the first year or so. Round about the beginning of my second year, they began to introduce VT-52 and VT-100 terminals with manual dialup acoustic couplers at a blazing 300 baud. There was one terminal that ran at 1200 baud that people would literally fight over (or come in when the lab opened and stay on it all day).
Anyway, back to the app: this is an emulation of an old tube terminal, including screen buldge/warp and variable brightness of pixels. Apparently, it even simulates cursor studder. Really makes one appreciate the state of computing these days!