What this mod does is allow you to see negative stack amounts rendered, which a helpful visualization for making 0 and negative stacks in 1.3-1.5. It works from versions 1.3.0 to 1.12.2, but between 1.8.0 and 1.12.0, the mod does nothing (this is because negative stacks are already rendered in that version range). In 1.12.1-1.12.2 it has to stop the render from skipping if the stacksize is <= 0, and adapts to using a getter instead of a field access, but otherwise it's the same thing for all versions. This was mainly targetted at 1.3-1.5 but basically I had a lot of time on my hands :P.

v1.0.0 renders "1" on single items, v1.0.1 does not. I guess it's personal preference, but imo "1"s are just unnecessary.