iOS 8 focuses on health with a dedicated app to track fitness and heart rate, enables Family Sharing for easy app purchases among family members, and enhances accessibility with new keyboard features for blind users. It includes the iCloud Photo Library for seamless access to photos across devices, upgraded messaging capabilities with audio and video, and expanded Touch ID support for third-party apps. New Siri features allow song recognition through Shazam, and iCloud Drive offers cloud storage for documents.