The users of Android 6.0 preview version can now start using the tool called Now on Tap by installing a new version of the Google Search application. Google had already announced the Now on Tap tool a while ago, but did not include it in any of the Android 6.0 builds so far.
Google Now on Tap works after installing Google Search 5.3 on devices which have Android 6.0 Preview 3. You can start using the new tool by holding your finger on any random screen for a certain period of time. The Now on Tap tool then tries to read the text on the screen and searches for relevant words or links in that piece of text.
Google Now on Tap uses the Hierarchy Viewer in the Android OS, in order to find out which content on the display is important for you, and while you are using your mobile device, it will already google it for you in the background. After the Now on Tap tool has found relevant and important information, it will present the results to you automatically.
According to numerous Android forums and websites, the Now on Tap function is not stable yet and regularly crashes the Google application, while it is trying to display relevant searches. Now on Tap is one of the many innovations that Google has announced to release in Android 6.0, which will be released before the end of September.
Next to finding relevant information for the users, the Now on Tap also renews the layout of the launcher in the Google Now-launcher. The Google Now launcher displays the Android 6.0 main menu, with an alphabetical list, which the users can scroll through vertically. The same thing applies to numerous widgets, which also form vertical lists.
In order to be able to test out Google Now on Tap, you will have to be a beta tester of Androids latest OS, which is simply called Android 6.0 Marshmallow.