Step1: we do need a case for blueIOT, here it is … send it to your 3D printer and select a cool wrist band (e.g. Sony SE20 – 24 mm size).
Step2: you do need an algorithm to count for examples steps. Here you go: external link (Analog).
„Note: Please use caution when using this battery in wearable projects. When using conductive thread, a short in the thread can create sparks and heat. We recommend using coin cell batteries for beginners.“
blueIOT is the perfect answers as it is running on a single CR2032 coin cell!