This plugin is open-source. Please feel free to contribute here: https://github.com/llamositopia/chest-sort/
ChestSort is a Bukkit plugin that was created to replace the functionality of InventoryTweaks' chest sorting features, due to NoCheatPlus' inventory.fastclick limitations. It works through the /chestsort and /invsort commands.
It also allows for custom implementation of new sorting methods by use of a public interface, for developers wishing to sort using an in-house method.