The difference here is Google requires you to give a specific location (e.g., an "instance" of McDonalds), whereas my tool helps you decide which location to stop at when there are many workable options along your route.
It's still baffling to me that they got rid of multiple-stage trip routing. Sure, you can drag the route to add waypoints - but it's nowhere near as precise as providing an address, and gets complicated once you start needing to add three or four stops along a route.