Just finished my version of a counter.
It works depending on what item in smart chest you want to observe.
pic1
Just a lillte bit of tuning to set the right item and here we go! A counter! 
(bottom of pic1 shows how it counts and what it counts)On the right there is a first version on how to program lights to show a single number (at this case - third number).
Here, as an example, I managed to count bullet magazines.
pic2
In pic3 there is compact version of light programming (first and second number).
pic3
Of course, this one is extendable if you want to add a fourth number 
Here is a link to save:
click
P.s.: don't worry about the wire mess!!! It all for science... for factorio 
