Smart wearables have been hailed as the next big thing in technology, with smartwatches leading the way.
Shipments of these wearables are expected to grow from 9.7 million units in 2013 to 135 million units in 2018, predicts the research firm CCS Insight. By 2018, it said, more than half will be smartwatches.
These are wristwatches usually paired with a smartphone via Bluetooth to offer smartphone-like functions. That is, they can alert you to incoming calls and messages, as well as upcoming appointments.
The first wave saw the likes of Kickstarter poster-child Pebble and others flooding the market. Soon, giants such as Samsung and Sony entered the fray. All these makers developed their own operating systems.
Then last March, Google announced Android Wear, a mobile operating system (OS) for smart wearables such as smartwatches and Google Glass. It integrates Google Now technology, such as Google Voice Search, and mobile notifications into a smaller form factor.
With Google Glass seemingly going nowhere fast, Android Wear's best use is for smartwatches.
Switch faces as you wish
Last September, Apple announced its Apple Watch to much fanfare, with fashion and tech heavyweights in attendance.
Mr Nick Spencer, senior practice director of ABI Research, which focuses on mobile devices and mobile developer ecosystems, said: "Apple entering the smartwatch market is good for consumers and good for competitors. It gives the competition plenty of room to work in."
With iOS and Android having the largest user bases, the coming smartwatch war will most likely be Apple Watch versus Android Wear, just as in the mobile OS arena.
Apple Watch has been set an iffy early 2015 release date, but Android Wear smartwatches, such as Sony's SmartWatch 3 and LG's G Watch R, have already landed.
A major feature of interest in these Android Wear devices is that the watch faces are switchable.
With the new Android Wear 5.0 software, developers can now easily create - and sell - watch faces. A dedicated section for watch faces has already emerged in the Google Play Store.
Mr Melvin Lee, 27, who describes himself as an educator, relishes being able to swop watch faces on his LG G Watch R. It gives him the feeling of wearing a different watch each time he makes a change.
"When I go hiking, one of the watch faces would instantly give me information on weather, my altitude and direction.
"When I go for a black-tie event, I would switch the watch face to one that is classy and formal," he said.
Digital Life takes you window shopping for Android Wear smartwatches. And we share our favourite Android Wear apps with you.