Apple launched the iPhone 4S in October 2011. Key features included an improved 8 megapixel camera, the powerful dual-core A5 processor, and Siri voice assistant. The iPhone 4S retailed starting at $199 for a 16GB model. Apple marketed the iPhone 4S through a variety of traditional and digital channels, targeting professionals, students, and other groups. The phone was distributed through Apple retail stores, online stores in 36 countries, and third-party retailers.