I'm specifically talking about the package Spacemacs enables. It creates a tiny square with a horizontal bar, that goes up and down in accordance with your position in the file you have opened. E.g., if you're halfway down the file, the bar would be in the middle of the square.
Also, there's a number beside the square, with a percentage, giving you what percent down the file you are. So, in the above scenario, it'd say 50%.
Does anyone know what this package is, or how to enable this feature?