Just done a quick audit of the iPhone apps that I actually use, there are 4 unfortunately that are not supported:
Ironically these are pretty much the only non built in iPhone apps that I use. Only Sonos has a suggestion that there is an app on the way for WP8. I've contacted the others and they have no intention of supporting WP... bummer
There's no doubt that the WP is far more capable than the iPhone, my 720 had massively more potential than the iPhone 5, but without the big apps you're not going to buy it, without people buying it the apps are not going to be ported... so do you buy to add to the numbers to break the circle?
Strava is on my list too. There is an app called Chaser that connects to Strava and will upload your ride info. I have only used it once because I have a Garmin, but it worked. Also Cyclometer is supposed to be able to connect to Strava and be an even better solution. I haven't tried that one yet.