At the start of my GF (getting fit) journey I purchased a FitBit Flex to kick start it off.  I researched a lot of  different trackers and this one seemed to be the best for me.  I loved the fact that it came with an iPhone app (I LOVE apps!) and that it wasn’t super huge.  The previous model did have some skin irritation  concerns with people, but I never seem to have issues with anything so I just disregarded that and went ahead and bought it.  It lets you know your steps per day, miles you have gone, calories burned and a sleep tracker.  The sleep tracker *bonus* ~sooooo cool.  I really didn’t realize how little I slept each night.  Well, now I do!  The silent alarm is also a huge win.  I love that it gently vibrates my wrist to wake me.  Only once when I was uber tired did I not feel it.  I’d have to say that all in all I am glad I bought my FitBit (although now they have a better heart rate model) and will probably upgrade eventually.  I’d have to say that the only down side I’ve found is the lack of durability with the wrist band (see photos).  I’ve gone through quite a few.  You are able to wear them 24/7 but it seems to wear down the material quickly where they start to separate at the seems.  Also I really like the lighter color bands but they get so grubby and don’t really clean off very well.  So if you’re looking for a little kick in the butt to get you motivated I’d recommend the FitBit.