Best Gadget for tracking excercise Walking / Biking /Running

Whats your gadget you like to use? I am looking for one to track everything biking / running / walking / swimming / heart rate possible
I have an Iphone and in the past used the Nike plus running shoes chip when and had some good success. I would like somethinking like an app or actual watch / device to track it all and add wirelessly to MFP or some where similair.

Thanks mucho,
Donna