This may be a bit late for you, and you may already have an Apple developer account, but there is a pretty simple way to do this. It is advertised everywhere for flash cs5, but in a flash device it is a bit more complicated.
- go here and upload the file. The password is 1234.
- extract these 2 files to your desktop.
- in your flex mobile project, navigate to the default package folder in the src folder under your project name on the left and open the main-app.xml file. Change the id value to "com.gamevil.zenonia2" without quotes. (This is necessary for this p12 certificate to work with its application in the Flash compiler.)
- create the final release by going to the project-> export build of the release and click "Next" in the first window after you are satisfied with the settings.
- finally, select the mobileprovision file and the p12 certificate, which should be on the desktop and enter the password (1234).
what is it! Flash Builder will now place .ipa wherever you specify, and just drag it to itunes and click sync. Please note that .ipa will only sync if there is a jailbreak device with appsync installed. let me know if you need more information about jailbreaking. Here is my post on the topic from my blog.