A DM tool to create details.
Is being a Dungeon Master (DM) a challenge? If you have to improvise creatively on the spot, you might think so. DM's use lists and dice to randomly chose details, like: d100: Familiar Behavior There even is a website with more D100 lists.
Now imagine, with one click of the mouse prints a small text block containing a detailed, unique yet fully randomized NPC. All details are chosen beyond the scope of a d100.
Next time my party walks into a tavern and ask the DM what people are inside, we have a rng-tool to come up with memorable characters.