I use and recommend the Misfit Shine, not only is this a nice product for monitoring Activity levels, the company has good support and stands behind their product. They have replace two of the devices I have.
This one is expensive, but by monitoring my weight everyday I have lost 30+ lbs.
Blood Pressure Monitor: (I have one like this)
Each of these items send data to their own website, and to an App on my iPhone.
The Health App on iPhone allows you to view all of the data in one place.
The next step is to use: Ifttt.com to record this data into a google docs sheet.
An example of one of these recipes is: