The Nike+ is the granddaddy of fitness trackers, and might have just been too early for its time. It is designed to fit under the insole of the Nike+ ready shoes, and measures your pace, distance, time elapsed and calories burned. This information is transmitted wirelessly to your device for real-time feedback while you train.
I happen to own a pair of the Nike+ shoes. Nike has since moved on beyond the Nike+ sensor. As it turns out, the cutout inside the shoe is a great place to store my Xiaomi band tracker. It also works for the HPB Actva Step Tracker. Nike has since moved on towards the Nike+ bands, and the world has also since shifted its attention to the Fitbit. As for the Mi band, it has great function. I like the great battery life and Google Fit compatibility. It’s just that it isn’t the nicest looking fitness tracker. The rubber silicon strap is rather ugly. I spruced up the look with the leather strap, but then that isn’t suited for running. I don’t like to bring my G Watch R along when exercising for the exact same reason as leather and sweat don’t really work out, so the Xiaomi band in my shoe works for a nice compromise.
In terms of accuracy, it misses some steps as compared to having the Mi Band on my wrist but otherwise, it does give a good representation of daily activity, tracking runs etc.