Today is the 10th anniversary of the iPhone first going on sale.

Since June 29, 2007 Apple has sold more than one billion units of the smartphone worldwide.

An iPhone is sold nearly every second on online marketplace eBay, with 2013's iPhone 5C surprisingly the most popular model.

Eleven generations of the device have been released, and Apple is reportedly planning to unveil a special 10th anniversary edition in September.

The modern smartphone did not yet exist a decade ago and the iPhone has helped transform how we use technology and access the internet.

Many of its functions are taken for granted in 2017 but it wasn't long ago when what's seen as everyday now was amazing.

Here are five ways the iPhone has changed in its first 10 years:

No App Store - The App Store, home to every addictive game and service a user could need, did not appear until 2008, so adding and customising features to the phone was not an option. In fact, the original iPhone offered just 15 pre-installed apps, including the calculator, stocks, maps and weather apps.

Touchscreen - Until the iPhone, physical keyboards had been present on all of the biggest sellers in the mobile phone market. The iPhone was the first to successfully make the switch to multi-touch screens and virtual keyboards, eliminating the stylus at the same time, which had been popular on other touchscreen and PDA devices up to this point.

News Shopper: Apple CEO Steve Jobs with the new iPhone at the Apple Worldwide Developers Conference in San Francisco

A single camera - Back in 2007 selfies were yet to take off, but even if they had, taking one on an original iPhone would have proved difficult as it did not have a front-facing camera. Even the rear camera was only two megapixels, far less than most selfie cameras today. In comparison, the current iPhone 7 houses a seven megapixel front-facing camera.

Social media - With no social media apps available to use, updating your Facebook or Twitter would involve using the web browser - which at this stage was still known only as Web and not Safari as it is today.

iPod - In a nod to its previous great product success, the app we now know as Music was called iPod on the first iPhone. Indeed, Steve Jobs even referred to the original iPhone as a phone combined with an iPod when announcing the device, rather than a smartphone.