At Google I/O 2014 Developer’s conference, Android Wear has an official announcement from Google and two devices were available on Google Play Store initially, LG G Watch and Samsung Gear Live. Android Wear gadgets will be compatible with most of the devices which is running Android 4.3 and up versions. Even though if you have an android smart phone with 4.3 or upper versions, i suggest you to cross-check whether your device is compatible with Android Wear or not.
How To Check the compatibility?
Google has made this process simple. Just open the following URL http://g.co/WearCheck from your Android device to check whether your device will be compatible or not. If your device is compatible then you will get a screen like below.
As of now LG G Watch and Samsung Gear Live are the two smart watched launched with Android Wear. Soon Motorola will launch Moto 360.