Tomek

Writes in the slidebar the numbers of tags

Tag counter

Writes in the slidebar the numbers of tags

ajayver

This plugin adds a small counter to each image in your posts. It is convenient if you have 10 or more images in each post and people want to mention some of them in their comments. 
Now they can easily see the number of the image. 
The plugin doesn’t touch you database and doesn’t change your posts content it works as a filter “on the fly”.

Image Counter

This plugin adds a small counter to each image in your posts.

Tag counter vs Image Counter