BlockEffects is a light-weight 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.
Plugin has more tha 7k downloads.