I got a Fitbit Flex and been having so much fun with it. I have been enjoying the challenge of reaching 10,000 step in a day. They say that is the recommended steps that an average healthy person should be taking. It also tracks your water intake, food/calories eaten, minutes you are active and you can also set reminders throughout your day to get moving, drink water, eat a meal….. whatever you would like and it will vibrate for your reminder.
A really cool feature that I like is at night setting it to log your sleep. When you wake in the morning it will show how you slept. It tracks minutes you are restless and moving around. It also track minutes you are awake. Like if you have to wake up and use the restroom it will track how long it took you from wake up until it senses you are back to sleep. Pretty cool!
I got mine at Target for $99 and they also carry them at Costco right now too for a few dollars cheaper. I do prefer my Polar Watch over the Fitbit to track my calories burned in a workout and for the heart rate monitor feature it provides. So yes, I wear all my gadgets in a workout to track my progress. I do wear my fitbit all day long though and my polar just for a workout. The Fitbit needs charging every 5-6 days. It has a little battery inside the wrist band you just slip out and charge. My Polar watch runs off a battery that you eventually have to change out. I have not needed to change out my battery yet and I have had my Polar for 2-3 years.