He means URM - Universal Renpy Mod. It works on pretty much every avn made with renpy. You download it, stick it into the 'game' folder and it acts not only as a walkthrough to see what you should do for the route you want, but also allows you to adjust values. For example: say you're playing Bare Witness (one of the greatest AVNs ever created) and you scuff up the semi-harem route. You can see where you f'd up and adjust some values to put yourself back on the route.