If you've seen our website before, chances are you've read one of our most popular articles from last year. It explained the blocking of the app, and reasons for it.
Check it out: http://www.fitzweekly.com/2013/07/gba4ios-blocked-no-more-pokemon-on-your.html
The new app, GBA4iOS 2.0 will be distributed from a different source with a new means of distribution. It was released, Febuary 18th, 2014.
Check GBA4iOS 2.0 out: http://gba4iosapp.com/
UPDATE #1: The new distribution developer account has been shut off, so to download or play the app after a reboot or first time download, you must set your date back to February 19th, 2014 or earlier.
UPDATE #2: The dropbox sync has not functioned due to development pieces still being involved, so in a few days the app should update through the auto-update function.