Watch Os 3 for the Apple Watch: An Easy Guide to the Best Features The Watch IOS was released in April 2015. It has 4nmm by 38 mm resolution and is available in Stainless steel, Silver aluminium, space gray aluminium, 18-karat gold, space Black Stainless Steel and 18-karat rose gold. The watch OS comes with six different straps. Your Watch OS depends solely on your iPhone to input information, services and apps. Most of the information will basically be on your iPhone, even though it will have a small amount of storage for images and apps. Apple Watch IOS is designed with Bluetooth, a built-in processor, NFC chip, sensors as well as a microphone and speaker.