I use Strava and am very satisfied with it. I am not sure whether I would call it a training tool, more of a training overview but I guess you can use it as a training tool. My use of it is pretty basic though. I track routes, kilometers and how much I have trained over the month. I also try to top the leaderboards if I can. I am ashamed to admit I have actually gone out once specifically to tackle a fast one.... I did not make it, got in 3rd lol. It was fun though. It is silly, but also kind of a fun way to stay involved and track your performance over certain parts of your rides. You always want to be faster, but if you also go up in rank on some list by going faster, it provides this little mini-game that makes tracking progress and doing your best just that little bit more fun. Especially if you have a friend always trying to best you