The Nokia Lumia 635 with Windows Phone 8.1 is now available through many parts of Europe and APAC at a very attractive price of $189 (before taxes and subsidies). Besides running the latest version of Microsoft's mobile OS, the device features a 4.5 inch display, 4G LTE connectivity and a 1.2GHz quad-core processor.
With Windows Phone 8.1, customers will also get access to some of the newest Windows Phone features, including Microsoft's voice activated digital assistant Cortana and the Action Center which manages notifications. Microsoft has done a great job in implementing Cortana, which acts as an alternative to Google Now on Android and Siri on iOS. You also get a series of Nokia apps like HERE Maps, HERE Drive and Nokia Music .
Even though the device comes with only 512MB of RAM, the Windows Phone 8.1 platform runs just as smoothly, so you wont be facing and lagging or stuttering on your Lumia 635. However keep in mind that certain applications on the Windows Phone store, like graphics intensive games, may require a device with 1GB of higher.
At $189, the Lumia 635 costs lesser than the devices like the Motorola Moto G, which is a 3G only device. But keep in mind that you get double the RAM. If you want the Moto G with 4G it will cost you $220. Those who want a more affordable Windows Phone 8.1 device, could consider the Nokia Lumia 630, which is cheaper and nearly identical, but comes without 4G.
The Lumia 635 is also offered in a selection of vibrant colors, and users can purchase different colored shells if they want a fresh look for their device. The Lumia 635 is definitely a clear winner for anyone looking for an affordable and capable device running Windows Phone.
source - Nokia | GSMArena