Export GPX from App
What's missing in the Strava mobile phone app is a feature to locally export the gps data (gpx or other appropriate format like tcx...) so it can be opened in another app like a map. This is a feature I know e.g. from Wahoo Fitness. There you have the option to "Open in..." (on iPhone), next step is to choose file format, finally you get to choose the app which you want the file to be opened with.
This feature woudl be really handy to check a track you or an athlete you're following on a local map app while not able to use a full blown computer.