Apple has released its iOS 8 SDK, the biggest developer release ever with more than 4,000 new APIs, giving developers the ability to create amazing new apps like never before. iOS 8 allows developers to further customize the user experience with major extensibility features like Notification Center widgets and third-party keyboards; and introduces robust frameworks such as HealthKit and HomeKit. iOS 8 also includes Metal, a new graphics technology that maximizes the performance of the A7 chip and Swift, a powerful new programming language. “With more than 800 million iOS devices sold worldwide, the opportunity for developers is huge,” said Craig Federighi, Apple’s senior vice president of Software Engineering. “This…