John Mueller announced on Google+ about the updated user agent for the Googlebot for smartphone.He said that, “FYI Googlebot just got a new iPhone, and is using it to check out your website."
Google also updated their blog post from 2014 with the new details in which they have mentioned that to give webmasters greater control, "Googlebot-Mobile" will be retiring soon for smartphones as a user agent is going to start in next 3 to 4 weeks’ time.
Now , the user-agent for smartphones will identify itself simply as "Googlebot" but will still list "mobile" outside the user-agent string.
This change will only affect the Googlebot-Mobile for smartphones. The user-agent of the regular Googlebot will not show variation, and the remaining two Googlebot-Mobile crawlers will continue to refer to feature phone devices in their user-agent strings.Google Brings New Googlebot For Smartphones!,