Ask HN: Is there any interest in Ghost Trainer App for runners/cyclers?

I personally miss some kind of sport tracker app, that would allow to compare my progress live in the field, with some kind of Ghost Trainer, where I would see on a map if I'm slower or faster then previous recording or even compare myself with others.

App could eventually yell at me if I would lag too much behind or motivates me some other way.

I did found some GhostRacer for Android (currently has some issues with segments from Strava), but still thinks there is place for another app.

What do you think, is it worth spending time creating one? Or anybody willing to join me?