Google has added a new section to the search app. Personalized, the section shows personalized search results from other Google services where the user is subscribed, including Gmail, Google Calendar, and Google+.
Using the feature, you can search for different emails and photos (stored in Google photos). And as you can see, the results are private, unless you make them public.
Functionality is possible for desktop and mobile clients. If the Personal Sector is not displayed immediately, you can find it in the ‘More’ menu.