This app shows the current time in three different cities around the world. If the time is between 6am and 6pm, a sun icon is shown, otherwise a moon icon is shown.
Click on the name of a city on the phone to select a different one. The selected cities are automatically synced across to your Android Wear smartwatch (if you have one) when it is connected to the phone via BlueTooth. Tested on both round (Moto 360) and rectangular (Sony smartwatch 3) watch faces.
If you have a smartwatch, please also check out HandyListPlus and HandyGPS which also work on both your phone and smartwatch.