iPhone owners in the Apple Beta Software Program with iOS 9 installed can easily update to the latest developer version (currently iOS 9 beta 4). This short process will install bleeding edge firmware features on the iOS 9 device, however the developer beta may encounter more problems or incompatibilities than the official public beta. In any case, those with iOS 9 already installed can upgrade to iOS 9 beta 4 by following these instructions:
The number of iOS 8 installations continues its upward march towards the 80 percent threshold. This magic number represents the iOS 7 adoption rate at roughly this time last year. While iOS 8 lags slightly behind according to Apple's Developer page, other reports show that the 80 percent level has already been reached.
In any case, iOS 8.2 was released on March 9 and is the first version to include Apple Watch support. In addition to stability enhancements and bug fixes, iOS 8.2 also includes several improvements to the Health App. iOS devices still running iOS 7 has dropped to 20 percent, with older versions comprising just 3 percent of the total. As always, these statistics from Apple only include devices compatible with iOS 8.
The iOS 8 installation rate continues to tick upward ever so slowly. Upgrades have slowed since late last year, with 69 percent of compatible devices currently running iOS 8.0 or later. Two weeks ago the number stood at 68 percent, which points towards a plateau in updates to iOS 8 amongst iPhone, iPad and iPod touch users.
Apple's App Store Distribution page illustrates current iOS usage in a pie graph, with iOS 7 at 28 percent and previous versions comprising just 3 percent of the total. All of the statistics were collected as of January 19th, 2015.
Holdouts with iOS 7 installed on their iOS 8 compatible devices now account for just 33 percent of total users. Apple metrics collected on the App Store point to a slowdown in iOS 8 installations, which initially soared in the early days after release. Still, the number of iOS 8 adpotions continues to tick upward.
The total number of iOS compatible devices running iOS 8 currently stands at 63 percent. This leaves only four percent of newer hardware running iOS 6 and earlier firmware. The jump from iOS 6 to iOS 7 was a more dramatic redesign, with users installing the update at a much faster clip.