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.
Read more about the plugin or download it on SpigotMC. The plugin is fully open-source, code available on GitHub.