What is Windows Phone ?

Windows Phone is a  smartphone operating system developed by Microsoft. 
Windows Phone is the successor to Windows Mobile.

What types of Applications I can develop ?

There are several types of application categories :

1. Games
2. Entertainment
3. Social
4. Tools and Productivity
5. Information & Promotion

Why to build Mobile applications ?

1. Making Money
2. Contact with Customers
3. Offer mobile version for Desktop/Web Application
4. Publish Media
5. Deliver location based information

And More !

What is the Development Environment for building Windows Phone Applications?

Environment : Visual Studio 2012 or Visual Studio 2013

Programming Languages : C# , VB , C++ , HTML5 & CSS

SDK : Windows Phone SDK 8.0

Windows Phone Development Life Cycle

Well, It's a very easy & organized Development Life Cycle :

1. Planning : It's the first important step in building any application . Good Planning for your application well produce a successful application.

2. Develop Application : You can develop windows phone application using Visual Studio ( If you are new to windows phone development or you still don't
have the required programming skills ; You can use Windows Phone App Studio : A web based development environment that allow you to create and build rich
windows Phone Application without writing Code !) .

3. It's time to run and test our application on Windows Phone Emulator or test it on a real device.

4. Finally : It's time to publish your application to the store !

Now. Monitor your application and read the feedback from users about your application !