Yota Devices has announced that the YotaPhone is now on sale, offering the best of both - but we don't mean Hovis. Instead, meet the device that brings the smartphone and eBook reader together.We first saw the YotaPhone at CES 2013 and our first impressions were that it was a good idea. Now we have had a proper play and we go hands-on with the final device, that's now on sale in various countries around the world.Design and buildIn terms of design, the YotaPhone is sleek, comfortable to hold and a good size for one-handed operation. The E Ink rear display has a soft and warm to touch matt finish, making it pleasant to hold and we quite like it.From the front of the device, it isn't anything out of the ordinary but when you flip it over you get the camera lens and YotaPhone logo with the E Ink display, which we liked the design of, it looks great.The YotaPhone changes in width from the top to the bottom, which actually makes for a good feature and offers something a little different to what is currently available on other devices.The build of the YotaPhone itself feels solid and we don't suspect you will be disappointed with what you get for your money with this device. It measures 133.6 x 67 x 9.99mm and carries a weight of 146g, which feels light enough but certainly not cheap.Alongside the dual displays, you'll feel like you have a premium device in your hand and the design is something the company should be proud of.DisplaysThe main feature of the YotaPhone is its dual screens and we were impressed with the 4.3-inch E Ink display on the rear. It gives you what you would expect it to and everything from Twitter to a map is clear in the grey scale image presented. The rear display offers a 360 x 640 resolution, which doesn't provide an exceptionally sharp image, but the detail on maps is pretty clear, better when zoomed in, and reading is easy. E Ink is known for great contrast and that's what you get here.When it comes to the front display, the YotaPhone has a 4.3-inch 1280 x 720 pixel LCD screen. That puts it in the middle of the park for current Android devices, but at 341ppi, it's sharp enough. The colours were bright and the image looked good, but we weren\u2019t hugely impressed with the viewing angles.The whites weren't particularly white, and when we placed it alongside the Moto G, the latest Motorola handset came out on top. We really like the idea of being able to customise the E Ink display, whether it be adding a picture to have as your wallpaper, or including certain widgets such as time, date and weather.It is relatively simple to do, despite the handset we played with being in Russian, and if you have a certain image you want on your main display, you can have it on your rear display too, which is a nice touch.Both displays can function simultaneously and they both come with gesture control panels for dual control.PerformanceRunning on the Android 4.2.2 operating system and a 1.7GHz Qualcomm Snapdragon S4 processor, the YotaPhone is slightly behind the majority of premium smartphones in terms of numbers on the spec sheet.When it comes to the operating of the device, Yota Devices has gone for its own gesture-based system with four main commands rather than the standard three-button keys on the majority of Android smartphones.The gestures include a right-to-left swipe to return home and a two-finger swipe from the top to the bottom of the main LCD to send the screen image or app to the E Ink screen on the rear, both of which we struggled with from time-to-time for a speedy response. Things seemed a little sluggish.Moving between pages when reading on the E Ink display wasn't quite as seamless as we hoped for either, but it could just be something that takes some practice. It's worth bearing in mind we were comparing it to our experience of reading with Kindle, where page turning is much easier and faster in comparison although with time, this might be different.However, we found the device was smooth and quick to react for every day tasks such as switching between apps and opening different features, as well as switching between the displays, which is done in the top right-hand corner.CameraWe didn't have a great deal of time to play with the 12-megapixel rear-facing camera but from the short period we did have with it, the YotaPhone seemed to provide some decent shots.When we snapped an image, the final result appeared on the E Ink display, showing those we had taken the picture of what they looked like in black and white. We didn't expect it and it's a good touch.Although we didn't have a chance to get a selfie in, the front camera is only 1-megapixel which is slightly less than most other smartphones available, so it might not be such a good performer: something we'll examine in more detail when we bring you a full review.Battery life and memoryThe YotaPhone has an 1800mAh battery under its hood, along with 32GB storage. There is no microSD slot for further storage expansion but when it comes to battery life, Yota Devices claims this handset will have seven to ten times the battery life of other smartphones in reading mode. That comes down to the display technology being used here, as E Ink is very sparing with power consumption.Naturally we weren't able to test the battery in the time we had with the device but we love the idea that you can have an address, map or other information on the E Ink display even when the phone has run out of juice.Built in appsThe YotaPhone comes with a number of built-in apps such as a real-time calendar, Bookmate for reading and MapsWithMe to feature on the E-Ink display.However standard apps are also compatible and social media networks such as Facebook and Twitter can be mirrored on the lower-power consumption screen to update in real time so you'll always know what is going on.There is one slight problem if you are an avid Kindle or Barnes & Noble fan, in that the respective apps don't have the right-hand corner functionality built-in and therefore you won't be able to read your books from these apps on the E Ink display, only the main LCD display. This is a shame but Yota Device's CEO,\u00a0Vlad Martynov,\u00a0did say it could be something that is available on its second generation of YotaPhone, due to come out in the later part of next year.ConclusionCEO Martynov\u00a0concluded the launch of the YotaPhone with the statement "we truly believe smartphones will never be the same after the YotaPhone launch" and in fairness it has at least put a different perspective on things. It is set to be priced around \u20ac499, heading towards the premium end of the Android market and you get quite a lot of smartphone for your money.We really love the design of the YotaPhone and we think the idea of E Ink screen is great, especially as you can have a piece of information like a map or address when your battery has died. Yota Devices have patents for software allowing you to switch between the displays and the design itself, so it might be a while before another device like this is released.The gestures could take a while to get used to, and while we found them a little slow at times, it might be a different matter after a little practice. With no Kindle app support as yet, it could be worth waiting to see what the next generation YotaPhone brings. But if you can't wait that long and fancy a smartphone that is a little different, then it's worth giving this device a go, but bear in mind there's strong competition on all sides, with higher spec models at the same price, or very capable models that are more affordable. The real sell here is that second screen and how well you can put it to use.