Years ago I tried to teach myself guitar.  That short lived experience taught me about the mechanical metronome and its importance in keeping up with the beat. Metronomes are easy to purchase but would look awkward if used during a performance.  The Soundbrenner company, located in Germany, has developed the Pulse; a smartwatch specifically made for musicians. It’s an actual wearable metronome which keeps you playing music in synch by alerting you through lights or vibrations.  You can wear it on your arm or even your leg and multiple Pulse devices can be linked together.  The Pulse runs off of batteries which can last up to 5 hours.  Soundbrenner is working towards bringing the Pulse to market this upcoming November with a retail price of $149.