The end goal of the apps are very similar, though Footpath places a greater emphasis on the route building + editing UI, as well as what you can do with map layers.

One aspect of EasyRoute that is pretty awesome is its support for exporting turn instructions to Wahoo + Garmin GPS devices via FIT files (the developer works for Wahoo by day), while Footpath only supports exporting the route data to GPX files right now.

Hope that helps.