Google has started rolling out v5.3 of its Google app that enables Now on Tap functionality on the third Developer Preview of Android 6.0 Marshmallow.
Google had first introduced Now on Tap back at Google I/O this year. The feature is an evolution of Google Now and allows it to display cards and other information depending on the content being displayed on the screen.
To use Google Now on Tap, all you need to do is grab the latest version of the Google app APK and install it on your Nexus running the latest Developer Preview of Android 6.0 Marshmallow. Then, simply press and hold the Home button for a few seconds in emails or conversations with your friends and Now will pull up a bunch of cards related to the information present in your conversation or email.
Now on Tap does not work on Lollipop or below, but the latest version of the Google app does bring the new Marshmallow style vertical app drawer to devices running Android 5.0.
You can wait for the Google app update to show up on the Google Play Store or download it manually from here.
[Via Android Police]