Upon the release of the Apple iPhone 4S, the Siri voice-recognition technology that is included with the new smartphone's accessories made a significant impression on those who had a chance to use it. Dag Kittlaus, co-founder and CEO of the company responsible for the feature, was reported to be leaving the company, according to All Things Digital.

The news source reports that Kittlaus' departure stemmed from personal reasons, and that his split with Siri was entirely amicable. It was stated that he wanted to spend time away from the industry to develop fresh ideas and be with his family in Chicago.

Kittlaus had been CEO of Siri since 2007, and previously spent time working with Motorola and as Entrepreneur-in-Residence at the Stanford Research Institute. He is cited as being instrumental in streamlining Siri's development, beginning with Apple's April 2010 acquisition of the company and continuing until his recent decision to leave Siri.

According to the San Francisco Chronicle, some applications available for phones using the Android mobile operating system are similar to Siri in some ways, but they do not match the full breadth of its functionality.