Android/iOS: It can be tricky to stay on the right path when you're trying a new running route. RunGo solves that problem with turn-by-turn directions. They offer city tours that pass by scenic and historic locations, and even a few fun shapes, like the Darth Vader face above. You can also create your own. RunGo's featured routes include this tour of the National Mall in Washington, DC, and this run on the Wildwood Trail in Portland, OR. In Sydney, runs include this loop from Kirribilli to Taronga Zoo and back, and this beer run from Surry Hills to Canterbury Hotel. Famous races are in the database, too -- here's the New York City Marathon.
I took RunGo for a test run this morning. It directed me to a twisty trail, indicating turns in key places, although it's no substitute for knowing how to read trail markings. If you stray from the route, the app doesn't recalculate your path. But it does show you a map with the route in blue and where you've been in red, so I found it easy to get back on track.