Lumia 635
The AT&T Lumia 635. Microsoft

The Nokia Lumia 635 is one of the most popular Windows Phone budget smartphones. It was launched in June 2014 with 512 MB of RAM. However, because of its popularity, an upgraded version featuring 1 GB of RAM was launched in February this year. Amazon is selling the AT&T edition of the Lumia 635 with 60 percent discount off-contract.

The retail giant is offering the 512 MB RAM edition of the Lumia 635 along with Prime shipping for only $39 off-contract. It is a limited offer that ends on Aug. 15, Phone Arena reported.

The regular price of the handset on Amazon is $99.99. With the 60 percent discount, the Lumia 635 can be a great entry-level device that users may want to use as a secondary phone. Phone Arena says one of the best features of the Lumia 635 is the offline GPS navigation.

The Lumia 635 comes with Windows Phone 8.1 OS onboard, but it can be upgraded to Windows 10 Mobile and buyers can even try the preview edition of the operating system on it. However, the device will not be supporting Continuum, a feature that lets users use the handset like full-fledged computer by connecting to a docking station.

The Lumia 635 is fitted with a 4.5 inches display that offers a resolution of 854 x 480 pixels. It supports a pixel density of 221 ppi. The device is powered by the low-end Snapdragon 400 chipset that features a 1.2 GHz quad-core processor. It is supported by 512 MB of RAM.

It is enabled with an 8 GB of inbuilt storage, and its expandable storage supports up to 128 GB of RAM. The rear camera is of 5 MP. However, it does not feature a secondary camera at the front.

The Nokia Lumia 635 is single SIM device that supports 4G LTE, 3G, Wi-Fi 802.11 b/g/n, aGPS and Bluetooth. It is equipped with a battery of 1830 mAh capacity. It produces a 3G talk time of 14 hours.