Microsoft Windows Phone Version History and Available Features

List of Windows Phone Versions

This table describes the list of Windows Phone OS versions and their release number.

List of Windows Phone SDKs and their support for Windows Phone App Development

Note: You can use the Windows Phone 7.1 App feature in Windows Phone 8.0 App, whereas you cannot use the Windows Phone 8.0 App feature in Windows Phone 7.1 App.

Features that are Available/Not Available

1. You can upgrade the application that targets Windows Phone OS 7.1 to OS 8.0.
2. You cannot add a reference that targets Windows Phone 8 in a Windows Phone 7 project.

OK. How to target my app in Windows Phone 7 and Windows Phone 8?

There are a few shortcut ways to make your app run in both WP7 and WP8.

1. Create a Windows Phone OS 7.1 app that runs in both Windows Phone 7.1 and Windows Phone 8

In order to do this, ensure that you do not use any of the Windows Phone 8 controls or features that make your app fail to run in a Windows Phone OS 8 targeted device. Do use the common controls and features that are applicable to both OS (7.1 and 8).

2. Create Windows Phone 7.1 project and Windows Phone 8 project individually

In order to do this, create the WP7.1 and WP8 projects separately. The cons of this is that you must update both projects for changes. Hence, this is not professionally recommended.

3. To use "Upgrade to Windows Phone 8.0" option

• In order to do this, create a Windows Phone 7.1 project using WP8 SDK. Name the Solution as MyAppVersion. Rename the project name from MyAppVersion to MyAppVersion71.
• In File Explorer, create a copy of the project in the same solution folder and rename it to MyAppVersion80. Now add this project to MyAppVersion Solution.
  So now, you will be having as seen in the following image.
• Now right-click on the MyAppVersion80 and select "Upgrade to Windows Phone 8.0". This will upgrade the project from Windows Phone 7.1 app to Windows Phone 8.0 app.
• Now define a conditional compilation symbol using the #define directive in your code or the Build page of the Project Designer.
• For Instance, define "WP8" in the Windows Phone 8 project and use like "#if WP8 {...} #endif" to isolate the source code to use the Windows Phone 8 related features.
• Ensure that both projects share the same source code and resources.

Features available in Windows Phone OS 7.1 and Windows Phone OS 8.0

The following are the most important features that are available in the Windows Phone:

Windows Phone OS 7.1 Features	Windows Phone OS 8.0 Features
CDMA Support, Deeper FacebookIntegration	All features in Windows Phone OS 7.1
Messaging and social integration	Support for WXGA (1280×720, 1280×768) resolutions, 1080p screen resolution support
Search/Bing	Support for MicroSD cards, IE10
SkyDrive, Microsoft Lync, To-Do, Office 365	Simplified porting of Windows Store apps to Windows Phone 8
Video Sharing via MMS, Facebook, SkyDrive and email	Nokia map technology
Integration to People Hub and Twitter	Native 128-bit Bitlocker encryption, Secure Boot
Pin any album to Start	In-app purchases
Deeper Multimedia Support	Possibility to take screenshots
Camera Enhancement	Kids corner, Rooms, Live Apps
Multiplayer Games Support	Google accounts. Windows Phone 8 now supports the CardDAV and CalDAV protocols that allow people to sync Google contacts and calendar information when they get new phones
IE9, Increased Security	Global Screen Rotation lock menu item.
Support for 16 new languages	New Driving Mode feature to ignore calls and texts
Hidden WiFi network support	Access Point menu item to set-up MMSand Internet Sharing
East Asian handwriting recognition
Internet sharing
Third-party application multi-tasking and fast application switching
Silverlight + XNA support in the same application screen
New sensor API combines compass, gyroscope and accelerometer
LTE support
Location awareness icon

For more features related information, please refer to http://en.wikipedia.org/wiki/Windows_Phone_version_history.