The Apple Watch is more than just a toy to track your health. You can also use it to control your computers and interact with your home automation system. MacID for Apple Watch happens to be an innovative app that lets you lock and unlock your Mac from your smartwatch. You will also be able to control your music.
MacID for iOS also lets you use your smartphone to control your Mac. For instance, you can use TouchID to unlock your Mac. You can try the app for under $1.