Previously, when they still dominated the market, feature phones gave manufacturers a bit more latitude to produce concepts that left the beaten track. The golden age of feature phones saw three very different shapes rub shoulders: candy bars, sliders, and flip phones. Today, any manufacturer seeking to launch a phone with highly unique technical specifications, like a round screen, would be faced with two obstacles. The first is that existing operating systems, essential to keeping any smartphone running smoothly and generally developed by third party companies like Google with Android and Mozilla with Firefox OS, are simply not designed to work with this configuration. Furthermore, applications, which have become very important in the eyes of consumers over the years, would not all be compatible because their developers would not have taken this specification into account.

It is consequently becoming far less common to find models like the Bang & Olufsen Serene, Golden Buddha Phone, Toshiba G450, or the surprising Elfoid, a cell phone shaped like a person that never got beyond the concept stage. However, some manufacturers are still trying to go off the beaten track. Here is our detailed look at the unusual smartphones out there.

Monohm – Runcible

Credit where credit is due. Monohm’s Runcible is in a league of its own as the most surprising smartphone of recent years. Its round shape is immediately eye-catching, and the surprises continue on the back of the case, made entirely of wood. The phone runs on Firefox OS. Beyond its design, the manufacturer created the phone to express a certain philosophy of life. The device does not come with a speaker, making a hands free kit essential. The stated aim is to force users to keep their attention on the world and people around them.

Google – Projet Ara

Shelved for several years, the modular smartphone concept becomes a reality this year with Project Ara from Google. Behind this name is a real mobile phone made up of modular components. Except here, you have no need of expert knowledge of electronics to change parts. They come in ready-to-use blocks that just need to be purchased and fitted together to make a full smartphone. Then it becomes possible to improve its different features, or to easily replace a malfunctioning block. A number of industry players have already joined the project, including Yezz (who presented its first blocks at the last Mobile World Congress), Toshiba, SolidEnergy, Nvidia, and more. The other aim of this project is to produce highly customizable smartphones. Not only in terms of specifications and appearance, but also features, since prototype blocks already exist to measure the level of oxygen in the blood, or even radiation.

Kyocera – Solar Phone

Several years have now passed since the French company SunPartner developed the only solution of its kind: a solar film for cell phones and tablets called Wysips Crystal, that boasts the unique properties of being both ultra-thin and highly malleable. This means that it makes an invisible addition to most flexible surfaces, which allows it to be placed on a smartphone or tablet screen and used for solar charging, without the slightest impact on the device’s design or thickness. And yet, it has been a good many years before SunPartner’s technology could be included in a smartphone: the Kyocera Solar Phone is the result. It is a waterproof, reinforced smartphone for outdoor use, making solar charging a particularly useful addition. This smartphone featuring Wysips Crystal will doubtless be the first in a very long list.

Yota Devices – YotaPhone 2

Seen from the back, the YotaPhone2 is just a traditional smartphone. But from the front, it reveals a unique feature: a second e-ink screen. This kind of display usually found on e-readers, is always on and consumes very little energy. It enables users to read content from various applications like news sites or social networks, without compromising battery life.

Motorola – Moto X and Moto Maker

When it launched the Moto X in 2013, Motorola made its mark. And yet, the smartphone itself boasted specifications that while perfectly serviceable, were nothing revolutionary. What made the device stand out was Moto Maker, its system for customizing its design. Of course, it only changes the device’s appearance, but with hundreds of possible combinations and quality materials like leather and bamboo, the Moto Maker service provided unprecedented levels of customization that have not been matched two years after its launch. The manufacturer has brought Moto Maker back for the new Moto X.

Samsung – Galaxy S6 Edge and Galaxy Note 4 Edge

Flexible screens have been fashionable for two years already. The first devices featuring such technology, the Samsung Galaxy Round and LG G Flex, were designed purely for manufacturers to test the market. Samsung then changed its strategy when it revealed the Galaxy Note 4 Edge in late 2014. This device came with a curved screen on one side only, with new features to make use of this additional display. But the Note 4 Edge was merely a test run for the masterpiece that would follow: the Galaxy S6 Edge. With two curved screen edges, it has surprised the entire planet by breaking away from decade-old smartphone design codes, and it will be remembered for that if nothing else. The curved screen is far from being its only asset, as it also boasts all the features of the traditional Galaxy S6. This means it comes with the best available screen, as well as the most high-performance camera ever seen on a smartphone.