How to integrate Google Now into your app (for a quick demo, view: https://www.youtube.com/watch?v=_UBvl_edu1o)

androidmanifest.xml

<activity
    android:name=".SearchActivity">
    <intent-filter>
        <action android:name="com.google.android.gms.actions.SEARCH_ACTION" />
        <category android:name="android.intent.category.DEFAULT" />
    </intent-filter>
</activity>

SearchActivity.java

/**
 * Somewhere in your activity
 */
String query = "";
if (getIntent().getAction() != null && getIntent().getAction().equals("com.google.android.gms.actions.SEARCH_ACTION")) {
    query = getIntent().getStringExtra(SearchManager.QUERY);
}