Sebastian Staacks, an individual developer, created the GB Interceptor, a device that allows the capture and livestreaming of games without modifying the GameBoy console itself.
Could be very useful
One of his motivations for developing the device was a Tetris enthusiast who contacted him and told him he wanted to play Tetris live on a Game Boy. Another motivation was that some of Tetris's online contests require an actual GameBoy console, and modified or compatible devices are not allowed, which made livestreaming very difficult.
Source: there.oughta.be
Contributed by nado