Fossil Watch Sport Smartwatch Smokey Blue Silicone FTW4021P. Fossil watches lets you track your heart rate, track your workout, even swimming, customise your dial and more. Smartwatches powered with Wear OS by Google are compatible with iPhone and Android phones. Wear OS by Google and other related marks are trademarks of Google LLC. Touchscreen smartwatches powered with Wear OS by Google require a phone running Android OS 4.4 or iOS 9.3 . Supported features may vary between platforms.