When organising (I use that term super loosely!) a hike, I wanted to be able to see how many kilometres it was going to be. The tool I use to use when I would travel and map a possible jog / run I would use Map My Run, so I resurrected my account to map the hike from Malabar to Watsons Bay. Part of it will overlap the Bondi to Manly walk.
I'm sure there are web and normal apps that allow for hiking path drawing to follow but it's funny how the mind just wants a simple option and has a "go to".