Almost every sleep tracker on the market requires some sort of wristband or mattress pad. The S+ is different. It sits next to your bed and can wirelessly track your sleeping habits. The sensor is quite small, but it is placed inside of a stand to ensure that it can properly record your breathing and heart rate. Altogether, it's about the size of a milk carton. The minimalist design helped it blend well with my furniture, although in some bedrooms it may stand out. There is no battery on the S+ and it must be plugged in at all times to function. It connects using a normal Micro-USB port and adapter, however the adapter also has a second port for charging your smartphone.
As you are about to go to sleep each night you must enable sleep mode on the sensor. You would think that the S+ could automatically enter sleep mode, especially given how smart it is, but this is not the case. Early on I went a few nights without sleep tracking because I would forget to enable the S+.
Enabling sleep mode must be done from your Android or iOS device using the company's mobile app. You will then be asked about your stress levels throughout the day, how many alcoholic drinks you consumed, how many caffeinated drinks you had and how long you exercised for.
A so-called "Smart Alarm" feature can be set to wake you up at the optimal time within a time frame you indicate each morning. The alarm didn't feel all that smart to be honest and I'm not exactly sure how it determined the "optimal" wake-up time, but nevertheless it got the job done and woke me up around the time I requested.