I created this plugin a little while ago, the code is garbage but it's very light on the server and works reliably.
- Native Minecraft Version:
- Tested Minecraft Versions:
While looking at a sign, run the command "/createcounter <material> <x> <y> <z>" where material is a valid bukkit material you would like to count (https://hub.spigotmc.org/javadocs/spigot/org/bukkit/Material.html) and xyz are the coordinates of the container. The sign will display the amount of items of that type that pass through the container.
Running "/deletecounter <num>" will delete a counter based on the number it is in the config. Check the config to figure out which counter number is assigned to the counter you want to delete.