SportTracks is a workout log for cycling, running, etc. It is in the same general marketplace as TrainingPeaks and WKO4, among others.

It exists as a subscription-based online service and as PC software (ST3). I started using the PC version in 2008 and I've uploaded every ride in there for the last nine years. It offered hooks for third party extensions and there was/is an active developer base adding features.

Several years ago they added an online, mobile-friendly service that still has traction though I don't think it has the user base of TrainingPeaks, not to mention related but significantly different services like Strava. I've stuck with the PC app so I'm not familiar with the online version.