It's the third day of Mobile World Congress (MWC) in Barcelona, and device makers are battling to show off what they hope will be the tech winners of 2015.

The showcase has already been used by Samsung to unveil its latest smartphones - the Galaxy S6 and S6 Edge - in the hope of fighting back against U.S. rival Apple.

And it's not just phones at this year's event - companies are also showing off a vast range gadgets including smartwatches, bicycles and even pet wearables.

Here, CNBC keeps you up to date with the latest product releases as they happen.

Chinese mobile phone manufacturer Gionee likes its devices thin, and this new model is no different.

Announced formally in Barcelona, the Ultra Smartphone ELIFE S7 focuses on an ultra-slim design, as well as performance and user experience.

"We believe ELIFE S7 will bring the future of slim smartphones to the next level," William Lu, the president of Gionee, said in a press release this week.

U.S. start-up Peel has created an app that lets you control your whole home via your smartphone.

Rather than using one app to turn off the light, one to control the heating and one to check the water sprinklers, this product lets users control all the different home appliances that are connected.

The firm - which was founded in 2009 and last year received $50 million of funding from Chinese e-commerce giant Alibaba - hopes its app can become the remote control for the home.

Chinese electronics giant Huawei has unveiled a stainless steel smartwatch, jumping into the hot market for wearable technology just weeks before Apple is expected to bring its own version to consumers.

The Huawei Watch, the Chinese company's first entry into the wearables market, runs on Google's Android wear and has a 1.4 inch round touchscreen face.

The device has a scratch-proof sapphire crystal lens, a heart rate monitor, and can detect the type of activity in which a user is engaged, such as running or cycling.

Linquet is a tiny plastic device that clips onto any item and uses GPS technology to send notifications to a smartphone.

If you are walking out of bar without your bag, the Linquet app will send a message to your phone, hopefully prompting you to run back inside and retrieve your valuables.

Chinese device maker ZTE released the Grand S3 on Sunday and its main feature is the ability to unlock the phone by scanning your retina.

The company said it planned to integrate this technology into mobile payments, so eye scanning could be used as a verification tool.

Handset maker Blackberry unveiled an "affordable" smartphone, and announced plans for devices including a dual curved-screen "slider" phone and luxury smartphone.

The 5-inch $275 BlackBerry Leap will be rolled out in April and is designed for "rising stars" in business, the struggling handset maker said at Mobile World Congress in Barcelona.

Blackberry's CEO, John Chen, also showed off a not-yet-finished "slider" phone at the event.

He told CNBC's Worldwide Exchange at Mobile World Congress that the company was also working hard on innovating its hardware.

"I'm really hopeful that our business is going to do well. In that last couple of quarters our hardware business actually made money," he said.

Some of the world's auto giants couldn't resist getting on the technology bandwagon this year, and U.S. carmaker Ford was no exception.

It moved from four wheels to two with its connected bicycle - or "e-bike" - which has a 200-watt motor and a battery that helps propel cyclists along to speeds of up to 25 kilometers per hour.

This kicks in when a users' heartrate goes above a certain level – that way you won't arrive at your destination in a sweaty mess.

In a world flooded by smartphones, the more basic "feature" phone has been sidelined, but one company - British tech firm Kazam - is still betting on the devices.

It internet-connected flip phone, called the Life C6, features an SOS button that automatically sends texts or makes calls to pre-registered numbers.

"People assume it's just little old ladies using feature phones, but actually the market is bigger than that," James Atkins, co-founder of Kazam, told CNBC in an interview.

Microsoft has released two budget smartphones with free Office 365 in an effort to tempt users ahead of the launch of Windows 10.

The two devices - the 5-inch Lumia 640 and larger, 5.7-inch Lumia 640 XL – are further low-cost releases by Microsoft as it looks to boost its market share in a fiercely competitive smartphone environment.

The Lumia 640 costs around 159 euros ($178) and the 4G Lumia 640 Xl costs 219 euros, and both will be rolled out globally this month.

Samsung unveiled two flagship phones on Sunday, the Galaxy S6 and Galaxy S6 Edge, as it looked to reverse its fortunes after a tough year.

The South Korean electronics giant lost its dominant position in both India and China, and lost major ground elsewhere to Apple.

In response, Samsung showed off its metal-framed Galaxy S6 which analysts said was a much-improved device from the heavily-criticized Galaxy S5.

Samsung's second device was the curved-screen Galaxy S6 Edge.

The smartphone can be wirelessly charged and the edge of the device can be isolated to show certain apps, such as the weather or stocks.

Taiwanese smartphone maker HTC released the One M9 on Sunday.

As with previous HTC smartphones, its focus is on the camera. The company is also pushing customization features such as different apps appearing on the home page depending on whether you are at work or home.

Chinese electronics maker Huawei has unveiled two wearable devices: the TalkBand B2 and TalkBand N1.

The TalkBand B2 is a fitness band with a face that doubles up as a bluetooth headset. The TalkBand N1 is a bluetooth-connected set of headphones with internal storage to store music tracks, removing the need for a smartphone or music player.

Sony unveiled the 6.1-millimeter-thick Xperia Z4 tablet with a 10.1-inch screen on Monday, touting the device as ideal for both business use and entertainment.

The Xperia M4 Aqua is Sony's 299 euro ($339) smartphone, catering to an audience that wants high-spec smartphones at a low price.

It hopes the device will appeal to users in the fiercely competitive mid-range market.

Ikea has released a range of furniture that wirelessly charges your smartphones and tablets.

The technology will be built into bedside tables, lamps and desks made by the Swedish company.

It was only a matter of time before two of the hottest trends - 3D-printing and selfies - came together.

Swiss company Dacuda and Swedish company Volumental have designed an app that lets users scan their faces from all angles to create a 3D image, which can then be sent to a 3D printing company and be delivered to your home.

French telecoms company Orange has released a new smartphone, Klif, aimed at users in Africa and the Middle East.

Users will pay a one-off fee of $40 for a six-month contract which includes data, minutes, texts and the smartphone. This works out at $6.66 a month.