The second-generation Samsung Simband wearable is now in beta testing. Unlike the first Simband, this new model acts as a smartwatch as well as a fitness tracker; it has been redesigned, with a curved 2″ AMOLED display. The band is modular and features multiple health sensors. A clever feature is the hot-swappable battery, to enable constant use – even at night, when such devices are normally charged. Samsung’s Simband is a reference platform for developers, not a consumer device.