Here are the demo applications from the book Flex 4 Fun, by Chet Haase. To run an application, first select a chapter title from the top list, then the name of one of the demos in that chapter from the second list. Some demos, especially those with images, take longer to load. The source code for all of these applications can be found in buildable Flash Builder projects on the book's website at http://booksites.artima.com/flex_4_fun. You can also browse the source for each chapter by right-clicking (or control-clicking on a Mac) on the running application and selecting the "View Source" item in the menu.