Smartwatch timeline: The devices that paved the way for the Apple Watch

The first all-electric digital watch from the Hamilton Watch Company had LEDs. The time was shown with the push of a button. 

This smartwatch needed an adapter and receiver box to display a dotted TV image.  

This watch could store memos, calendar entries and also served as a calculator using a clip-on keyboard. Seiko also launched the UC-2000, RC-1000, the Memo Diary and the UC-3000 within one year.

The watch boasted a display caller ID and could also show updates on subjects from sports scores, stock prices and weather forecasts.

Steve Mann built the first Linux-powered watch. IBM launched the prototype in 2000.

It was designed to connect wirelessly with PCs, cell phones and other wireless-enabled devices. It could display condensed email messages and receive pager-like messages.

It had a 160 x 160 display, 2 MB of memory and Palm apps such as an address book, memo pad, to-do list and calculator. A stylus was integrated into the strap.

It received the award as the best of Comdex 2002.

Garmin has been involved in the GPS sports watch arena for over a decade.

The watch measured speed, distance, pace and calories burned. It used two AAA batteries which could give you about 14 hours of action.

The original Sony SmartWatch had a 1.3-inch OLED display and ran a modified Android version.

It often crashed inexplicably but was still well received by the tech press.

Samsung's smartwatch was kickstarted with the Galaxy Gear in 2013. It paved the way for the Gear Fit.

In 2014, Samsung Gear S was released, boasting 3G connectivity, meaning it doesn't need a smartphone to operate.

Formerly known as iWatch, it was officially revealed to a crowd in Cupertino in September 2014.