I know this isn't quite what you asked for, but...

If your goal is to track where you've gone, I recommend a Garmin Edge (preferably 500) over any smartphone GPS app.

• Much more rugged than a smartphone
• Battery life is 18 hours
(If your cell battery dies after half a day and you get into a jam, it's gonna be problematic)
• GPS performance is better
• works smoothly with Garmin Connect
• The 500 in particular is much smaller than any smartphone
• Can integrate with cyclometer, cadence meter and HRM (additional modules)

Some of the units also include on-screen maps (e.g. Edge 305 iirc) and still have 12+ hours of battery life.