IPhone 4 models. In fall 2010, pentalobe screws started to replace the Philips screws used in post-repair units in the US and in production units in Japan. The iPhone 4 shipped with iOS 4, which was the newest version of Apple's iOS mobile operating system at the time. iOS 4 introduced a multitasking system, allowing apps to remain "suspended" in memory, perform certain operations in the background, and allowing users to switch between apps using an on-screen menu. It also introduced FaceTime, which allows users to perform video calls between other iPhone, iPad, iPod Touch, and OS X users. The iPhone 4
People Power Company at Bitfone, which was acquired by Hewlett-Packard. People Power was initially envisioned as a greentech company with a focus on energy efficiency. In 2013, the company released its "Presence" app, which is designed to turn older smartphones and tablets into home monitoring devices and sensors using the device's built-in camera. The Presence app also allows users to monitor and control third-party internet-connected appliances and electrical usage in their homes. The app was originally available for iPad, iPhone, and iPod Touch devices. In mid-2013, the company's Chief Scientist, John Teeter, was selected as a Presidential Innovation Fellow and worked at the