I've been fighting the urge to buy one of those fitness wristbands (Nike+ Fuelband, Fitbit, etc) or a GPS watch to help track distance, pace, and sync with an online profile so I can track progress and compare and compete with friends. To feed my desire to track all things fitness I use a few apps that you might find useful to accomplish the same thing and maybe save yourself some dough when compared to those expensive wristband options.
I track my overall daily movements using the Moves app. I've used Moves every day since February of this year and I've really taken a liking to it. Its base functionality is that of a pedometer, but it offers much more. It also tracks where you walk plus activities like running and cycling. It can distinguish between the jiggles your car might send to the sensor and the legitimate wiggles your steps provide the accelerometer. It can approximate the number of steps you take each day and equate that to a time and distance of walking to help you get an idea of your level of physical activity each day. Moves is my gauge of how active I'm being so I know when I need to kick it up a notch.
Moves runs in the background using low level GPS sensing to tell you where you were when you were walking, running, driving, or cycling. It not only has a numerical representation of your activity, but it also provides a visual cue to the level of your activity and type by using different sizes and colors of bubbles around each activity type depending on how much you walked, ran, or rode your bicycle. I have Moves running the in background around the clock, even when using my Nike+ GPS or Strava Cycling apps and the data I get compares closely to what the activity specific app (Nike or Strava) gives me. I can't recommend it highly enough.
Nike+ GPS has been my go-to running activity tracking app for a few years now. It has social sharing and competition functionality to challenge friends and compare accomplishments. It also integrates with the music app flawlessly. The ability to customize the verbal feedback cues is great and there is also a feature that allows you to track the miles you put on your shoes so you can more accurately decide when to spend the coin to buy new kicks.
Strava Cycling is a great app for cyclists that allows tracking of rides, performance improvements, and sharing of social interactions like "kudos" and comments on rides. You can also see how your latest ride segments compare to previous rides as well as the community of riders that pedal their bicycles over those same segments. If you do have a Garmin GPS device, it can sync its data to the Strava website. If you want more, you can pay for premium access and get insight on more advanced data that might take your training to the next level.
RunKeeper is an all-in-one fitness app for tracking running, cycling, hiking, canoeing and many other activities as well including manual entry for any activities that you complete indoors on a treadmill or other training machine, like a stairmaster. It offers social connections as well, but I don't really dig its interface for some reason. However, I think it is a solid app, so that is why I'm giving it a mention. It might be the app for you.
Start Somewhere. Just Start Now
As with most things where progress is measured, if you never start you will never progress. There are several functions of each app I didn't discuss, but since they are all free you should grab them and try them out for yourself. If nothing else, start using the Moves app and see just how active you are. The data it reveals will be a great baseline to have whenever you sit down to plot your fitness goals.
Update - Moves
Wouldn't you know it, as soon as I post about Moves they release and update that adds calorie burn functionality.