maXPert displays how much more experience item needs to reach the maximum level.
It also tries to return upgrade items to their original inventory positions
Added experience is subtracted from the value, so you will know if you are wasting any experience.
Note: the two distillates in the example would normally add 5100exp, but empowering items can only increase items experience to max level+1 (3800 + 200), so the added experience is getting reduced to 4000. When maXPert notices that exactly levels worth of experience is getting wasted it will display a red warning text over the title bar, as there is a chance that added experience is being reduced.
Check the images section for another example of this.
Secret World Legends\Data\Gui\Custom\Flash\