Is this user agent string related to Safari?

It means the Safari on the iPhone that's running iOS 7.1 is using Google Search (Appliance) as it's default search engine.

I would like to pitch in on this. While I can not testify against i-CONICA's answer, as it is probably correct, I noticed that on both an iPad and iPhone (both running iOS 7.1) that if you open a website through the Google Search App, that the user agent will be changed to the "GSA" string, as opposed to the standard Safari user agent string.

It seems the culprit of this "GSA" string is people searching and opening a website using the Google Search App.