Although marketed as a fitness device, what the band really does is measure and track your bio-metric data before plotting that data to discover some insights about your lifestyle.
The wristband syncs to your phone (both iOS and Android) through a bluetooth connection which means the data is available to you at any time. With a glance at your phone's home screen you can see how many steps you've walked, your natural sleeping patterns, or how hydrated you've kept yourself.
The app will also suggest goals for you to accomplish based on the data the wristband has accumulated about you. For example to walk more, or drink more water, or go to bed at a certain time.
When the UP24 was first released it was advertised as having up to seven days battery life, but on the 9th of September Jawbone's executive director for systems engineering, Hari Chakravarhula, released a firmware update doubling the UP24's battery life.