Google announced a new feature for Google Now at its I/O 2015 in San Francisco. Google calls it as 'Now on Tap', which basically show contextual information by long pressing on the home button.
This feature makes the next Android OS smarter. The Now on Tap will offer contextual information based on what you are doing with just a click or by voice command. Yes, the 'Ok Google' voice command will also work from any screen to get contextual information.
For instance, if you and a friend are discussing about a movie, just long press the home button to get Google Now card with all the available information about the movie like, review, rating, links to the trailer, IMDB and showtimes.
The new feature will also works all the time no mater what you are using on the smartphone. If you are watching a YouTube video of a famous actor, activate the Google Now to get more information about the video or the actor.
Google Now identifies the details and then answers question directly without specifying the brand's name or even the actor or the song name.