Nokia Lumia 635 Windows Phone with 5MP Camera, Case and Car Charger Wouldn't you love to have a personal assistant? Meet the Lumia 635 and Cortana, your new best friend and tireless helper. Want to get ideas for dinner, directions to a party or a weather report? Ask Cortana. Want some time to yourself while still taking calls fromcertainpeople. She can help with that too. Add in a Windows 8.1 operating system, 8GB of memory and great camera and music functions and you have a phone that worksandplays as hard as you do. Just ask Cortana. She'll tell you.