Moves is a free iPhone app that automatically tracks your steps every day, whether you are walking, running or biking. You just have it running in the background and it updates throughout the day. It does a lot of the things the big boys do without having to carry around an extra piece of equipment. I've noticed some extra drain on the battery, but honestly not enough to be worried about.

https://itunes.apple.com/us/app/moves/id509204969?mt=8

I downloaded something similar and found that when I'm sitting at my desk I'm too fidgety and it was tracking steroids when i was actually seated

Ugh auto correct... Steroids = steps