I am seriously thinking about a fitness tracker to help me monitor my physical activity so I can optimise my diet and exercise. Before I take the plunge I was wondering if devices like FitBit or MiBand, which are designed to work with smartphones and related devices, need the smart device to be present all the time or can you download the data from the fitness tracker when convenient. Basically I use a Windows Phone and not all fitness trackers are compatible but I do have an Android tablet but don't carry this around with me all the time.