I used to have nervous hands and bit my fingernails. Now that I have a fidget spinner, I use my fingers to keep the fidget spinner spinning around in a fast circle. It keeps from shaking and my hands and fingers feel better keeping busy. I like looking at the gadget going round and round spinning in fast circles.I also like my six sided fidget cube. One side keeps my fingers busy like turning of and on a wall light switch. Another side has a circle that keeps my fingers busy keeping the circle moving. Third side is little black buttons I can keep busy pushing in. Another side has a raised circle that allow me to keep turning the cube around. I think my favorite side is the side with the metal ball and the three lines with the grooves in them. The groves feel nice on my fingers. I recommend these fidget spinners/gadgets. They keep my fingers busy and me less tense and nervous.
Product info: https://www.walmart.com/ip/159350459