iOS 11, announced at WWDC 2017, introduces over 30 new features and is compatible with various devices, including iPhone 5s and newer. Key features include the end of 32-bit app support, improved mapping data through drones, a video sharing app, more natural Siri sounds, dark mode, and contact availability status. Additionally, iOS 11 implements an enhanced iCloud voicemail feature and includes a QR code reader for users in China.