Siri is a virtual personal assistant feature in Apple devices. The feature uses a natural language user interface to answer questions, make recommendations and perform actions. Siri was originally developed by SRI International. SRI spun off Siri, Inc., in 2007, which launched a personal assistant app in February 2010. Siri, Inc., was acquired by Apple in 2010. Apple announced in October 2011 that the iPhone 4S would be using this technology; it has been included in all iOS devices released after October 2012.