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.
Apple Footer * iPhone X R and X S pricing is after trade‑ in of iPhone 7 Plus in good condition. Additional trade‑ in values available for a limited time only and require purchase of a new iPhone, subject to availability and limits.