iOS 10 will officially debut on Tuesday, September 13, available as a free download to any supported iPhone, iPad, or iPod touch device. Additionally, watchOS 3 will be released on September 13 for Apple Watch users, and tvOS 10 for Apple TV.
The iOS 10 release will arrive through the Software Update mechanism within the Settings app, but can also be installed with a computer using iTunes.
Most modern iPhone, iPad, and iPod touch hardware will support the release, but you can review the complete iOS 10 compatible devices list here
iOS 10 includes a variety of new features and refinements to the iOS experience, including a major revamp to the Messages app, with animations, custom sticker and GIF keyboards, handwriting, emoji conversion, a Maps app that now offers suggestions and table reservations, a redesigned Notifications center, a new lock screen, a redesigned Music app, new Photos app features including a Memories feature and facial recognition.
Multiple beta versions of iOS 10 have been released to developers and the public through the respective beta testing programs. Users running beta releases of iOS will also find the iOS 10 final version software update when it is widely available.
iOS 10 GM is available to download for beta testers right now, for both the developer and public beta testing programs.
Separately, macOS Sierra will be released on September 20 as a free download.