Apple still needs to have some accurate feedback from iOS developers to make iOS 5 free from any compatibility issues. iOS 5 beta 3 is the third pre release after the official announcement at WWDC event. You can experience the beta releases only if you have a developer account. Apple offers you a licensed account via a simple sign up process for $99/year. After that you can find out the technical information and tools related to iOS releases. You need to have the latest beta release of iTunes 10.5 for the working of iOS 5, you can get it from the Apple developer’s site.