In many sports, fitness and healthcare applications small and lightweight sensors as well as instrumented sport equipment are used for motion capturing, movement analysis or to monitor vital parameters. Those wearable sensors usually use inertial-magnetic measurement units (IMMUs) besides ambient (e.g. light), environmental (e.g. temperature, barometric pressure) or vital (e.g. heart rate) sensing components to obtain data. We develop (specific) wearable sensors for all kinds of purposes.