Timers are useful things to have at the gym and anywhere you need to time tasks. You can always buy one or build your own. Adafruit has shared a guide that shows you how to build a giant timer for your gym. It has 12″ tall digits, each made from a meter of NeoPixels. You are also going to need an Arduino, timer cabinet, car horn, and a few other parts to get started.
Much cheaper to build your own than buying one. You can find out more here.