Plugin Name:
Eternal Light
Link:
https://www.spigotmc.org/resources/eternal-light.50961/
Feature:
You are able to see where mobs can spawn, decided by the light level. Just as in the NEI Mod. It has permissions for server admins. Far better than spamming torches all over your build or walking every inch with the debug menu open.
Would be a nice Plugin if you want a mod free area 