Apple previews iPhone OS 4

DigiTimes: Apple has previewed its iPhone OS 4 software and released a beta version of the software to iPhone Developer Program members. The new release includes an updated Software Development Kit (SDK) with over 1,500 new Application Programming Interfaces (APIs) and over 100 new features that will be available to iPhone and iPod touch users in summer 2010, the company claimed.iPhone OS 4's new multitasking offers users a new way to move between apps, and provides developers seven new multitasking services to add multitasking features to their apps. These services include background audio, so apps like Pandora can play music in the background, and VoIP, so VoIP apps can receive a VoIP call even when the iPhone is asleep or the user is running other apps.iPhone OS 4 delivers mail experience on a mobile phone with its new Unified Inbox, allowing users to see messages from all their email accounts displayed together in a single inbox. Users can switch between inboxes to see messages from any single account. In addition, users can now thread their messages by conversation, making it easier to stay on top of email discussions. DigiTimes