Nokia Lumia 520
Some are using this devices for audio books, and eBook reading. It can also make a great phone for emergencies. It also includes a radio. Nokia Mix Radio lets you choose from over 150 mixes or generate your own playlists.
Comes with digital lenses built in—exclusive to Nokia. Add motion to your images with Cinemagraph. Type in a destination and HERE Maps will get you there quickly. Supports Cortana to answer all of your questions.
Note: Some apps will not run on the 520. The Lumia 525 increases RAM to 1 Gig allowing it to run all Windows phone apps. T-Mobile uses a Lumia 521 which is the same phone but has 1700 MHz coverage.
 Lumia 635
The Lumia 635 is similar to the 520 except it has a larger screen 4.5", larger battery, quad core processor, and 4G LTE support. The size is: 129.5 x 66.7 x 9.2 mm and it weighs 134g. Display size: 4.5" has a resolution of FWVGA (854 x 480) 221ppi. Standby time has increased to 25 days and talk time is 13 hrs for 3G (longer on 2G). Hardware camera button no longer on the unit and the side buttons are recessed. Ambient light and proximity sensors are no longer present. A SensorCore is added.
 Lumia 640
The Lumia 640 is a 5" screen version with an 8 MP camera with flash and a front facing .9 MP camera. It has screen resolution of 1280 x 720 and does HD video. It has 1 GB RAM and is upgradeable to Windows phone 10.
 specifications 520
- Platform: Windows phone 8
- Processor: Qualcomm Snapdragon S4, dual-core 1 GHz; GPU:Adreno 305
- Memory: RAM: 512MB, mass memory: 8GB (~5 available for user)
- expansion: Micro SD card up to 64GB
- Networks: WCDMA network: 900 MHz, 2100 MHz ..WCDMA max data speed DL: HSDPA - 21.1 Mbps ..WCDMA max data speed UL: HSUPA - 5.76 Mbps ..GSM network: 850 MHz, 900 MHz, 1800 MHz, 1900 MHz..GSM max data speed DL: EGPRS 236.8 kbps ..GSM max data speed UL: EGPRS 236.8 kbps
- Other networks: Bluetooth 4.0, Wi-Fi b/g/n
- Navigation: GPS -- aGPS -- WPS -- GLONASS -- no compass
- Display: 4 inches, WVGA (800 x 480) 235 ppi IPS LCD 24bit TrueColor
- Battery: Battery model: BL-5J, 1430 mAh, 3.7 volt removable.
- Maximum talk time (3G): 9.7 h, Maximum standby time: 16 days
- High Efficiency Charger AC-20 included and USB cable
- USB: micro USB 2.0 for interface and charging.
- Camera: 5 MP, auto focus with two-stage capture key, 4 x zoom, 28 mm focal length
- Audio: Nokia Music, Mix Radio, PlayReady, FM radio, added apps for other formats.
- recording formats: AAC LC, AMR-NB, GSM FR
- 3.5 mm and speaker.
- sensors: Ambient light sensor, Accelerometer, Proximity sensor
- Dimensions: 2.52 x 4.72 x 0.38 in (64 x 119.9 x 9.9 mm) (LxWxH)
- Weight: 4.37 oz (124 g)
 Specifications 635
- Software release: Windows Phone 8.1 with Lumia Cyan
- Size & weight: 129.5 x 66.7 x 9.2 mm, 134g
- Display: 4.5", FWVGA (854 x 480), TruColor (24-bit/16M)
- Technology: ClearBlack, IPS LCD, 221 ppi
- features: Corning® Gorilla® Glass 3, Lumia Color profile, Wide viewing angle
- Touch screen: Capacitive multipoint-touch
- Memory: data storage: In device, Memory card, OneDrive cloud storage, App and data storage on memory card
- Mass memory1: 8 GB
- RAM: 512 MB or 1 GB
- Maximum memory card size: 128 GB
- Expandable memory card type: MicroSD
- Free OneDrive storage built in up to: 30 GB
- Replaceable battery: Yes
- Battery capacity: 1830 mAh
- Battery voltage: 3.7 V
- Maximum standby time6: 25 days
- Maximum talk time (2G): 18.6 h
- Maximum talk time (3G): 13 h
- Maximum music playback time: 58 h
- Maximum Wi-Fi network browsing time: 9.4 h
- Maximum video playback time: 7 h
- Other user interface features: Vibrating alerts, Voice commands
- Keys and Input/Output Methods, Touch screen, Volume keys, Power/Lock key, microphone, speaker, 3.5mm audio plug.
- Accelerometer, SensorCore
- CPU name: Qualcomm® Snapdragon™ 400, Quad core
- Clock rate: 1200 MHz
- USB: USB 2.0 micro-USB
- Bluetooth: Bluetooth 4.0
- Bluetooth profiles: Advanced Audio Distribution Profile (A2DP) 1.2, Audio/Video Remote Control Profile (AVRCP) 1.4, Generic Attribute Profile (GATT), Hands-free profile (HFP) 1.6, Object Push profile (OPP) 1.1, Phone Book Access Profile (PBAP) 1.1
- Wi-Fi: WLAN IEEE 802.11 b/g/n
- Wi-Fi hotspot: Up to 8 Wi-Fi-enabled devices
- Other wireless connectivity: Screen projection
- Sharing: Peer-to-peer sharing: Lumia Beamer, Lumia Storyteller, Play To DLNA app
- Cellular: Same as 520 plus LTE FDD network: Band 20 (800MHz), Band 3 (1800 MHz), Band 7 (2600 MHz), LTE max data speed DL: 100 Mbps (Cat 3), LTE max data speed UL: 50 Mbps (Cat 3)
- Other specifications: Same as 520, (note: no camera button)
Included apps: Facebook, LinkedIn, Twitter, Foursquare, OneDrive, Picasa, Internet Explorer 11, Xbox music, MixRadio
- Lumia Camera, Lumia Cinemagraph, Lumia Panorama, PhotoBeamer, HERE Maps, HERE Transit
- Calculator, Clock, Calendar, Alarm clock, Reminders, Phonebook, To-do list, Family Room, Kid's Corner, OneNote, Social networks in Phonebook, Wallet, Notifications, e-mail, messaging, Unified MMS/SMS editor, TTS message reader, Windows phone store.