Since Microsoft acquired Nokia’s smartphone division, the company has focused its efforts on mid-range and entry-level handsets, where Windows Phone has been most popular. In less than two years, the Lumia line has welcomed 11 smartphones priced under $300, without a single flagship device. The Lumia 640 we are reviewing today is one of those sub-$300 devices. It's aimed at the upper segment of the entry-level market, priced at $250 unlocked. It's got a decent hardware package for the price and runs Windows Phone 8.1 out of the box, with a promised upgrade to Windows 10 Mobile later this year. The use of a Snapdragon 400 SoC is a little strange, considering Qualcomm’s newer 410 silicon is already available. The familiar chip has been paired with 1 GB of RAM and 8 GB of expandable storage. On the front, the device packs a 5.0-inch 720p LCD display. Cameras are also fairly standard, with an 8 megapixels shooter on the back, and one megapixel on the front, while on the design front Microsoft continues the long-running trend of colourful, plastic Lumia phones. Read the complete review.