Any pedometer will work to track activity.

Bottom Line Up Front:  This is a very cheap but effective pedometer.  It is made in China and I purchased it for about three dollars including shipping.  That being said, I just purchased a series 6 Apple watch. 

Pedometers come in all shapes, colors, and sizes.   Most are not extremely accurate at measuring steps or feature-rich choice, but it is great at estimating how close you are to the goal of 10,000 steps.  This pedometer does not have any spectacular bells and whistles but it will measure your steps and give you a quick and cheap guide to estimate your steps.  

Package Includes:  

• Mini Digital LCD Pedometer – multiple colors available
• No instruction but, to be honest, you don’t need them

Item Description:

• Mini Digital LCD Pedometer, Black
• Measure how far you ran or walked and store a record of your workouts in a fitness log
• Count steps cumulatively to a maximum of 39,999 steps
• Press the Reset button to clear step number memory 
• Press the Mode button to display in turn: steps/distance (mile, km)/ calorie (kcal)
• Built-in belt clip
• Size: 4.9 x 3 x 1.2cm
• Powered: 1 x LR44 button cell battery 

Links:

• eBay link: Insten Pedometer
• Amazon Link: Insten Mini Digital LCD Pedometer Walking Running Bike Step Calorie Distance Calculation Clip-on Counter, Blue

Figure 1:  Inside of Pedometer: This is a picture of the inside of the broken pedometer.  The bottom is the pendulum that swings and makes contact between the rectangular piece of metal at the bottom that appears to have two holes in it and the wire coming off the battery. Each time it makes contact that is one step.   

I used this pedometer for 1 week and dropped it.  The pendulum broke off and it no longer worked, so I took it apart to see how it works.  The one I have was made for a corporation named Insten.  There are lots of similar items on eBay.  I would ignore the bad review on Amazon.  It appears that the buyer got a non-functioning model.  I have ordered and tested three of them and all worked perfectly.  I did drop one about 10 feet down a set of stairs and it broke. 

Testing:

The blue pedometer is an electronic pedometer that has a mechanical pendulum.  It is situated in the plane that you would create movement when walking or running from your belt line.  I am going to compare this to my iPhone to give you an idea of how accurate the steps are.  If you look at the two charts of data, you will see the Insten Blue Pedometer counted 2,000 more steps over a week.  It is because the iPhone will not count single steps.  You must move about 10 feet to get steps counted.  The cheap pedometer counts everything as a step that moves the pendulum.  

Figure 1:  Insten Pedometer Data

Figure 2: iPhone Steps Week 1

Calories are clearly different.  The iPhone calculates active calories and the Insten blue pedometer calculates total calories.  I used a calculated BMR to calculate active calories to do a comparison.  The calculated numbers are different.  I am significantly larger in size than the average male.  I am 75 inches and weigh 200 plus pounds.  The average American male is significantly shorter and lighter.  I suspect the cheap pedometer uses the average in its calculation.  

Distances are nominally different.  This is probably from the average stride since it auto-calculates distance and does not ask for a stride length.   

The bottom line (2nd): Any pedometer can help you track your activity, but you get what you pay for.