We first caught a glimpse of Google's Project Ara modular smartphone early last year, but the company has just shown off a working prototype, and says an initial pilot program will begin in Puerto Rico in the second half of 2015. The update came at Project Ara's second annual developer conference held at Google's headquarters in in Mountain View, California.

If you're new to Project Ara, the idea is that you create your own smartphone from various pieces: camera, memory, processor, speakers, and so on. If you want a high-end camera but need to save money on the audio capabilities, for example, then Google's new concept makes it possible. The idea was first aired by Dutch designer Dave Hakkens with his PhoneBloks concept before it was picked up by Google's Advanced Technology and Projects (ATAP) division.

It also makes upgrades much more straightforward, because you don't have to toss out your aging smartphone if you just need a memory boost – you can simply slide in a new module. Eventually, it will even be possible to swap out a drained battery for a freshly charged one on the go. The Spiral 2 prototype demoed by Google this week is the first model to get up and running and sported a 720p display, though there's still a long way to go before a full consumer launch.

Google says that Spiral 3 – the next model in the prototype chain – will bring with it 4G connectivity, support for a broader range of modules (including those made by third-party manufacturers) and vastly improved battery life. Later this year, Project Ara phones will go on sale in a limited trial run in Puerto Rico, and feedback from the pilot scheme will then help Google develop the product further.

We've also seen a sneak preview of the Ara Manager app, the on-board software that lets users get everything working together in unison, and the Ara Configurator, which looks a little like Motorola's Moto Maker and enables buyers to configure a phone to suit their exact requirements before it's delivered. It's also going to be possible to add colors and pictures to the phone at the point of sale for a truly personalized experience.

The video below demonstrates some of the possibilities of Project Ara.

Source: Google ATAP