Acer Smart Band

they are all about the same.. just Pediometers.. plan and simple………..  what the acer provides is the Watch function and the additons of the connects to the  phone calls and text’s messages..

they measure how much you move your arm when you walk..  I found when I moved the band to my dominate arm it recorded more accurately. 

Also if you use a stepper or  stationary bike..or similar exercise equipment,  you can attach the tracker to your ankle to get that to record those exercises. as steps as well.. This was listed as a tip on one of the tracker sites.