As the name suggests, this plugin allows you to create your own menus. The menus are based on inventories, with each slot holding a clickable menu item. When a player clicks on a menu item, it performs all of the commands listed in the item's lore (the text underneath its name) in a similar manner to command blocks. You can design the menu in-game by selecting any item, naming it in an anvil, modifying its lore using a command, and using commands to create and open a menu for editing to place it anywhere in the inventory that you wish. You can modify your menus any time you want.

Plugin Link:

https://dev.bukkit.org/projects/createyourownmenus