[Jens] wanted a subscriber counter for his YouTube channel. He could have gone with a simple OLED, LCD, or LED display, but he wanted something more tactile and interesting. So he built a mechanical 7 ...

There are a variety of means by which numbers can be displayed from an electronic circuit, and probably the most ubiquitous remains the seven-segment display. Take seven LEDs, lamps, LCDs, VFD ...