System stability chart stopped updating
The original i OS 9 release in September 2015 fixed a security issue within previous i OS versions where a "flaw allowed anyone within range of an Air Drop user to install malware on a target device and tweak i OS settings so the exploit would still work if the victim rejected an incoming Air Drop file".
When a phone reaches 20% battery level, users are automatically prompted to turn on Low Power Mode, which changes the color of the battery icon in the top row status bar on the screen.
i OS 9 includes performance and speed improvements thanks to the expanded use of the Metal API.
i OS 9.2 also included a new visual download indicator in Apple Music, support for Wi-Fi calling for AT&T users, along with bug fixes and stability improvements.
i OS 9.3 was released on March 21, 2016, with new 3D Touch Quick Actions for several of Apple's built-in apps; Night Shift mode; Notes with password protection and Touch ID; News with better personalized recommendations, support for in-line video and i Phone landscape view; Health with Activity view; Car Play updates for Apple Music and Apple Maps; new languages for Siri; multi-user mode for i Pad in education; support for pairing multiple Apple Watches to one i Phone; Wi-Fi calling for Verizon users; support for playing videos encoded with Dolby Digital Plus audio streams to select Lightning-equipped i OS devices; i OS 9.3.2 was released on May 16, 2016.
i OS 9 comes with two important battery-saving updates.