This site creates 2D visualisations of an athlete's activities in Strava. Then different types of activities (Ride, Run, etc) are displayed as layers on various map tiles, which the user can select. The position, orientation and speed of the user is also displayed, and this can be hidden by de-selecting "My location" in the menu. The user can also select any activity, which will produce a link that the user can follow to the relevant Strava activity page.
This is currently deployed at: https://stravaheatmap.pythonanywhere.com/
Any questions: [email protected]. Cheers.