Apple has just released the fourth beta of their upcoming iOS 5 mobile operating system. iOS 5 was first introduced during the WWDC 2011 event in San Francisco.This beta version of iOS will only be available to developers who have enrolled in the Standard or Enterprise programs. If you are one of them you can download the beta here.
The first beta was released on the 6th of June, the second beta was released on the 24th of June and the third beta was released on the 11th of July.
Apple also released iTunes 10.5 Beta 4 to developers. The new version of iTunes is required to sync iOS 5 Beta 4 devices.