Looking for App to prepare track for Strava art


I want to run in the woods, and the GPS track of the activity should show a funny symbol. I would like to prepare the track with a freehand tool, where I can draw the artwork, then download the track and load it to some app on the smartphone that gives me instructions in what direction to run.

There sure are software tools for that. Please suggest what to use.


IMO best tool for it could be Brouter: https://brouter.de/brouter-web/