Custom routes gps app- does it exist?

There are certain scenic routes that I like to take but all directions are printed out. Basically shortest distance from start to finish is 30 miles but the scenic way with the good twisties is more like 70 miles long. Instead of having to have a co pilot read turn by turn directions, is there an app where you can plot your customized routes? I use Waze and of course there is no option for it. Any ideas