Building an application on Facebook gives you the opportunity to deeply integrate into the core Facebook experience. Your app can integrate with many aspects of Facebook.com, including the News Feed and Notifications. All of the core Facebook Platform technologies, such as Social Plugins, the Graph API and Platform Dialogs are available to Applications on Facebook.
Here is the steps to create a Facebook application.
1).To create a Facebook application first you need to register as a Facebook developer so go here and click on the button “Register as a Developer”.If you are already registered as a Facebook developer then you can skip to step 5.
2).Accept the Facebook terms and click on “Continue”.
3).Now Facebook will ask for mobile confirmation .Enter your mobile number and click on “Continue”.Facebook will send a confirmation SMS on your mobile number.Just enter the security code sent by Facebook and click on “Continue”.Now ,in next step Facebook will ask some information about you.If you are interested to enter information about yourself then you can enter otherwise you can click on “Skip” button.
4). At last Facebook will sent a confirmation message on your email id.You don’t need to take any action on that email it’s just for your information.
Now you are successfully registered as a Facebook developer,you can continue your application building.
5).Real steps for Facebook application creation starts from here .Open the link https://developers.facebook.com/apps and click on “+ Create New App” .
6).Now Facebook will ask for application name and namespace(optional).Enter your application name and if you need free hosting provided by Facebook sponsors then you can check the check box .Now click on “Continue”.
7).In next windows enter domains for your application.Facebook will allow only these domain to use your application.Now select how you want to use your Facebook application most of time “Website with Facebook Login” so you can select this option and enter the the URL of your website.Click on “Save Changes” and copy the “App ID” and “App Secret”.App ID” and “App Secret” will be used for building your own Facebook application in your desired programming language like PHP,Java Script etc.