Simple Stack 1.3.0 Changelog:
Simple Stack 1.3.0 is here! Since September, a new configuration GUI system and many bug fixes have been implemented.

Added:

• Allow items to be properly stacked together when on the ground
• Allow "unique items" (Items where all data needs to match) to be specified in a list in the config to allow for a specific item to have a custom stack size
• Allow a new default max item value to be set in config
• Add a config option to disable custom hopper stacking to improve performance
• Add a real-time configuration GUI in-game using /simplestack config

Bug Fixes:

• Ground items that usually stacked to 64 but were configured to stack to less than 64 could still be stacked together on the ground up to 64
• When a player has a full inventory, items could be picked up into armor slots
• Rare NullPointerException error when dragging items around in inventory
• Shulkers (sometimes other items) could be stacked in the inventory on top of items that weren't of the same type
• Fix bug where items stacking on the ground were not checking the config before stacking together
• Hoppers didn't stack items in their inventory upon initial pickup
• Rare AssertionError when unstackable items were moving through a hopper into a hopper minecart
• Too many potions could be moved into a brewing stand through a hopper resulting in item loss
• Entities without inventories that were picking up unstackable items would throw an error to the console
• Items that weren't armor could be put in armor slots of a player's inventory
• Add a few safeguards for potential NullPointerException errors
• Fix a few rare errors when saving the config in-game

Notes:

• This plugin now internally uses Mikedeejay2Lib (Already included in the plugin, there's no need to install it), source code for Mikedeejay2Lib can be found here
• This plugin now records plugin statistics using BStats, link to Simple Stack statistics can be found here
• Lots of text was added for the GUI of this plugin, if you're a translator and would like to contribute to updating your language, head to this plugin's OneSky site