I tried the Strava app, along with almost every cycling app available for an iPhone, and didn't really like any of them that much. Of all the apps I tried, I decided to use Cyclemeter, which has more data and customization than any of the apps out there that I've used. I initially thought they had way too much data and settings on the app, but now I wish they had a few more. If you put your rides on Strava, like I do, it will automatically share your ride with Strava, and other sites, at the end of the ride so you don't have to do it manually. It also does live tracking, similar to a Garmin, and you can set it to send your data by distance or time, which I don't think Garmin gives you those options. The only thing it doesn't do right now is turn-by-turn, but they say they are working on it for a future release.