Software updates are available to improve performance, fix bugs and add new features to devices. At least, that’s their intention. That’s why always recommends updating when the manufacturer makes a new version available.
Apple, in order to prevent old and vulnerable versions of iOS from being installed, stops signing them so that it is impossible to go back to an older version of the one we have on the iPhone and iPad. Also with the intention that users can not perform jailbreak.
However, Apple is still signing iOS 6.1.3 , a version of the company’s mobile operating system launched in late 2012. It has been more than 6 years since it was released, and it has usually been unsigned for at least 5 years. Why are users still allowed to install it?
It was thanks to a thread from Reddit that we were able to learn about this little curiosity. Confirmed by users who have been able to test it, the iPhone 4s and the iPad 2 can return to iOS 6.1.3 , one of the last versions of iOS before skeumorphism disappeared.
The latest version compatible with iPhone 4s and iPad 2 is 9.3.5 , launched in September 2015. However, due to optimization problems and the lack of hardware power, it does not work very well. That is one of the possible reasons why Apple can still sign iOS 6.1.3 on these two devices. However, some users comment that it is possible to install it because switching to iOS 7 requires iOS 6 first.
Knowing how careful Apple is with these details does not seem to be a mistake , especially since it is something that was discovered a year ago and, twelve months later, is still available.