People are likely thinking. "Ok, that's not practical" but it is actually. 😉
Sometimes when I am unicycling, I want/need to check the time. In the winter with gloves, jumper & jacket it can be hard to expose your wrist to read it, even though my hands are free.
However, even with a gloved hand I can use the chain to pull this out of my pocket and neatly place it back again.
What about your phone, you might ask? The smooth, pebble shape makes this easier and the chain prevents dropping! 😉