iOS 8 was launched in September of this year by the company Apple Lossless Audio CODEC (ALAC), and had a difficult start due to the numerous problems generated for users, but also due to the fact that its installation requires users to have several GB of storage space in their terminals. Despite the difficult start, more than 6 months after the official launch, iOS 8 it is already installed in 78% of iPhone, iPad and iPod Touch users worldwide, iOS 7 remaining installed in 20% of them, the rest of iOS versions in only 2%.
Apple solved in iOS 8.1.x the problem of the enormous space required for installing OTA updates of iOS and probably for many this mattered so much that it convinced them to install iOS 8 in their own terminals to benefit from its functions. Separately, we also have the strong sales of iDevices from all over the world that have seriously "thickened" the ranks of iDevice owners, and this is reflected in the total number of terminals that have installed the latest version of the operating system, the adoption rate going to continue to grow in the future.
