How to Setup a Custom App with a Custom Tab Icon using Woobox's IFRAMEHOST

1. Create New App

Visit https://developers.facebook.com/apps and click the Create New App button. Next type an App Name (This can be anything you want, the name you are going to call your tab would be a good choice), agree to the Facebook terms and click Continue.

2. Configure your App

Click the edit icon link to upload the icon for your tab. Next, click the Page Tab section under Select how your app integrates with Facebook.
Note your App ID at the top of the page. You need this App ID to create the URLs you need to enter in the App on Facebook and Page Tab sections,
Canvas URL - Enter http://YOURAPPID.iframehost.com/ (Replace YOURAPPID with your App ID)
Secure Canvas URL - Enter https://YOURAPPID.iframehost.com/ (Replace YOURAPPID with your App ID)
Page Tab URL - Enter http://YOURAPPID.iframehost.com/tab (Replace YOURAPPID with your App ID)
Secure Page Tab URL - Enter https://YOURAPPID.iframehost.com/tab (Replace YOURAPPID with your App ID)
Page Tab Name - Enter whatever you want your tab name to be
*** Make sure your Tab URLs end in /tab ***
After you finish entering those 4 fields. Click the Save Changes button.

3. Install your new App to your Page

Make a note of your App Secret (you will need to input it shortly). Enter the following URL in your browser to install your new page tab app:
http://www.facebook.com/add.php?api_key=YOURAPPID&pages (Replace YOURAPPID with your App ID)
Select the page you would like to install the tab on.

4. Visit your Page Tab

The first time you visit your page tab, you will be prompted to enter your App Secret into activate the tab.