Cloudless Fitness Tracking

A couple of years ago I bought a Fitbit Flex, the second generation (?) fitness tracker by Fitbit. It was at a time when I had just graduated from university and started my job, which involved a lot of sitting. (I wasn’t paid for the sitting part) I was interested in how close to the 10000 daily steps I got and the Fitbit provided this information. It had a very limited physical display consisting only of 5 LEDs which would consecutively light up as you approached the 10000 steps.