<accessibility-service
android:description="@string/accessibility_service_description"
android:accessibilityEventTypes="typeViewClicked|typeViewFocused|typeWindowStateChanged"
android:accessibilityFeedbackType="feedbackGeneric"
android:notificationTimeout="100"
android:canRetrieveWindowContent="true"
xmlns:android="http://schemas.android.com/apk/res/android" />

@Override
public void onAccessibilityEvent(AccessibilityEvent event) {
    final int eventType = event.getEventType();
    String eventText = null;
    switch(eventType) {
        case AccessibilityEvent.TYPE_VIEW_CLICKED:
            eventText = "Focused: ";
            break;
        case AccessibilityEvent.TYPE_VIEW_FOCUSED:
            eventText = "Focused: ";
            break;
    }

    eventText = eventText + event.getContentDescription();

    // Do something nifty with this text, like speak the composed string
    // back to the user.
    speakToUser(eventText);
    ...
}