Having a full-suspension mountain bike, there are some things, most notably the suspension, that require service at certain intervals, i.e. every 30, 40, 100, 150 hours of riding. TrainingPeaks has a way of tracking that info to let you know when maintenance is due, or to track mileage on shoes, and I was thinking that would be a useful feature. A little notification after a set number of riding hours would be really cool.
Datafield has no access to history. What you think about widget that looks on TP website(or any other) and lists your gear with hours left to a maintenance?
Right. You could definitely do it in an app/widget by accessing a web service (Strava, TrainingPeaks, Garmin Connect).
It is really unfortunate that Garmin has locked down access to the Garmin Connect web service. The data is all there in Garmin Connect. If access was granted, such an application wouldn't have to access an additional 3rdparty website.