It is designed mainly to make the usual very crowded channels like /world readable by allowing you to filter the shown messages using whitelisted and blacklisted keywords.
It works with a few simple features with an user-friendly(-ish?) UI :
Blacklist keywords showing in messages you don't want to see Whitelist keywords showing in messages you want to see and combine keywords like dungeons/raids and roles when looking for a group/raid/guild,
(currently,it only working for zhCN)