Android Wear is Google's port of the Android operating system designed for wearable devices such as smartwatches. At the time of writing, there are over a dozen manufacturers, such as LG, Motorola, Huawei, Asus, Fossil, and TAG Heuer, who make Android Wear watches:

The primary difference between the Android Wear platform and its competitor Apple's watchOS platform is the support of devices and screen sizes.

Unlike Apple Watch, which is currently available only in 42 mm and 38 mm rectangular screen sizes, Android Wear comes in the round, square, and rectangular screen shapes. They also come in various different screen sizes other than the standard 42 mm and 38 mm sizes.

Another key thing to note is that Android Wear devices can be paired using Android Wear apps for both Android and iOS platforms.

In this book, we'll be covering the topics involved in Android Wear application development and helping you master the platform for writing rich and powerful Android Wear applications.