Google invited “Glass Explorers” who had pre-ordered the wearable glasses at the 2012 Google I/O conference to choose and rank their devices. Thus came about the day when Google Glass was launched officially as a tool that was supposed to supply rich textual content and notifications through a heads-up display worn as eyeglasses.

The device additionally had a 5 MP camera and recorded video at 720p. Its diverse capabilities could be activated via voice command, which includes “OK Glass.” The tech giant also released the Google Glass associated app called My Glass. The first ever third-party Google Glass App appeared from the popular New York Times, thus enabling the app to read out articles and news summaries to its users.

Early in the year 2015, however, Google stopped selling the beta “explorer edition” of Google Glass to the public, following user and public complaints of its design and the hefty price tag of $1,500.

Optical head-installed display technology is still a relatively unexplored niche, but smart watches and activity trackers have taken on a somewhat popular role in modern lifestyle. Back in the year 2012, ABI Research predicted that the sales of smart watches could hit record figures of 1.2 million by 2013, owing to the excessive penetration of smartphones in many international markets.

The economics were also in favor of this prediction – low cost of MEMS sensors and a wide variety of available devices at competitive prices further aided the boom.

The smart watch was reinvented with the crowd funded backed start up Pebble in the year 2013 through a campaign runner on Kick starter that helped raise over $10 million in funding alone. By the end of the year 2014, Pebble happily announced that it had managed to sell over a million devices.

Pebble then went back to the roots of its crowdfunding venture to rake up a further $20m for the next-generation smart watch called Pebble Time, which was shipped all over the world in May 2015.