The Nokia Lumia 635 is a successor to 2013's super-popular Lumia 620 model. This new handset is an improvement in nearly every way. Microsoft's first release has a great-looking 4.5-inch touchscreen, a speedy quad-core Qualcomm 400 processor, a new, squared-off design and its the first device to run on Windows Phone 8.1. The new operating system improves many things, most important of which were the long-standing complaints about short battery life. When put to the test, the new Windows phone provided more than a day of heavy use on a full charge. There is also Cortana. Think of it as Microsoft's version of the "OK Google" or Siri. TheStreet's Technology Contributor Gary Krakow has details.