I've played with a couple - sorry, was a while back, can't remember which off the top of my head - but I do remember concluding none of them offered anything more that I wanted compared to Google's MyTracks, which is a surprisingly capable app for a freebie and seems quite stable. Not specifically designed for cycling, but provides all the usual stats I might like and a downloadable gpx file record for a trip. Biggest problem with phone-as-bike-computer using GPS is battery life, in my experience. I ended up getting a dedicated GPS for any rides longer than a couple hours.