MotionX-GPS is for your outdoor life:
That's Walking, Hiking, Running, Cycling, Biking, Sailing, Skiing, Flying, Racing, Geocaching.
MotionX-GPS shows your position and track at all times on street, topo/terrain and satellite maps. Follow your track back to where you started and email to multiple recipients with a single click your position, track, trip statistics (date, start time, elapsed time, distance traveled, average speed, etc.) and a picture taken along the way.
MotionX-GPS is the leading GPS solution for the iPhone, with over 4 million happy users. MotionX-GPS is exclusively designed and optimized for the iPhone.
Strengths: Incredible amount of features
Ease of use
Weaknesses: If you have an iphone it kind of eats the battery (about 3 hours constant use)
If you have any kind of Garmin or other stand alone GPS and an android or iphone put the GPS on ebay and buy this. It does it all and better than any GPS I've tried. If you are a cadence counter it's ANT compatible too. Superb app.