BlockEffects is a light-weight Minecraft plugin that activates special effects when players interact or step on the block. There are 5 trigger types: LEFT_CLICK, RIGHT_CLICK, WALK, BREAK, PLACE. On trigger you can send messages, execute commands, add potion effects & more. There is a built-in cooldown and per block permission. The plugin is ideal for KitPVP, SkyPVP and other types of servers.
At the time of writing the plugin has more than 10k downloads.
You can download it from SpigotMC or view source code on GitHub.