I use Endomondo. You can export your files and upload them to Strava using their websites. Not sure if you can export from Strava to Endomondo, so might be worth investigating before you plump for Strava.
Strava user here, it is kind of addictive, quite how long that'll last I don't know ... Already have several segments with identical PB times on them ;-)
You can export gpx from Strav, under an activity, Actions->Export GPX