Helper application to keep track of the advancements your bought and what your discount are.
Clicking on an advancement shows its details:
You are able to buy multiple advancements at once by checking multiple boxes. Buy the selected advancement (to get the discounts) by clicing "BUY: XXX" at the top right corner.
All data for the advancements are stored in the the following file: data.json. If any advancement is faulty it will probably be in that file the change is needed.