Grumpy Old Geeks Companies Walnut Company Walnut 2 mentions in 1 episode A company the hosts say plans to let electric skateboard owners rent out their boards through an app. Mentions 310: Spark Grumpiness Jan 10, 2019 31:23 There's a new company on the block called Walnut. 31:47 let individual owners of their skateboards rent them out through an app