IPhone 6 a byproduct of this lack of rigidity, the touchscreen's internal hardware being susceptible to losing its connection to the phone's logic board (nicknamed "Touch Disease"). The iPhone 6 Plus was also the subject of camera issues, including some devices with malfunctioning optical image stabilization or otherwise defects on rear cameras. The iPhone 6 and 6 Plus were moved to the midrange spot in Apple's iPhone lineup when the iPhone 6S and 6S Plus were released in September 2015. The iPhone 6 and 6 Plus were discontinued in most countries on September 7, 2016 when Apple announced the iPhone 7 and
IPhone 4 supports up to iOS 7, released in September 2013. Due to the relatively aged hardware of the iPhone 4, certain features available on newer iPhone models are not available on the device; as of iOS 7, they include Siri, 3D maps and turn-by-turn navigation, AirDrop, AirPlay mirroring, live camera filters, panorama mode and certain visual effects introduced by iOS 7, such as the blurring of translucent interface elements, the parallax effect on the home screen, and live wallpapers. While still subject to the same limitations, iOS 7.1 did bring some slight performance improvements to the operating system on the iPhone