![Iphone os 4 Beta 3](http://sanziro.com/wp-content/uploads/2010/05/iphone_os_4_beta_3.png)
Apple just released iPhone OS 4.0 Beta 3 to its developers, which unveil a brand new feature: double tap on the button to bring out the app switching pane on the bottom of screen, and you can now flick to the far left to bring out a new orientation lock button, new widget control for the iPod and a button to access the iPod app.
You can only download and install this prerelease software when you sign up for Apple’s Developer Program, which is US$99 per year. Apple released iPhone OS 4.0 beta about a month ago. Based on past release schedule, you can expect a new beta release every 2 weeks on Tuesday. The final gold release is expected in June but it is not clear if Apple will release the new OS before the new iPhone 4th generation iPhone hardware. Users of iPhone 3G/3GS and newer version of iPod touch can be upgraded to iPhone OS 4.0 but not all features are available to all models. For example multitasking is not enabled for iPhone 3G.