Not all devices are initially supported, and the choice is limited to several new products, including the LG Watch Urbane, Asus ZenWatch 2 and Huawei Watch.
ASUS bundled its wellness app for health tracking, and a Watch Face Land app to allow users to create their own watch faces for ZenWatch 2.
With a quick glance at the smartphone or watch, users will be able to see how close they are to their goal and stay motivated.
The search giant released an open source sample called Games in Motion to demonstrate how developers can make fun games using Google Fit and Android Wear.
The company's very first smart watch runs Android Wear and looks like a regular fancy watch; it rocks a sapphire crystal display with 400x400 resolution.
The device is touted to meld classic look with enhanced features, packing all of the usual sensors under its fancy hood.
The popular fitness tracking app also got support for headphone heart rate monitoring when connected to the SMS Audio BioSport Headphones.
The company foray into the smart watch market is impressive; the ZenWatch looks more like a regular watch than something only geeks would wear.
SmartBand Talk is a fitness band with an always-on curved 1.4" e-paper display; SmartWatch 3 is the company's first Android Wear-based watch.
Both devices look like traditional watches, making them appealing to the wider audience; they also pack an array of sensors to track users' fitness activities.