Over the last 3 months, I have spent time testing the accuracy and effectiveness of 2 activity tracking apps and essentially quantifying myself (a.k.a Quantified Self) based on steps taken and distance covered.
There are plenty of arguments out there on which app or device best measures the activity of a person. I have used both the Moves App and the Nike Fuelband concurrently.
Below is a chart comparing the measured steps captured by both devices. You can see that the measured steps do overlap in some areas and peaks of either device over the other during different days.
This helps me to understand that you should select the app to measure your activity based on what you need to know about yourself. It is also good to know the margin of error so as to compensate for any device which over measures certain activities.
I hope to have more data in the coming months and I can share more as I analyse the data.