Assistive touch on Galaxy Note 3 adds a floating icon to call/perform 12 different task. The icon always stays on top and you can enable Assistive touch to be able to do some of the functionality of the device easier.
To use Assistive Touch on Galaxy Note 3, do as follows:
1. Open Settings and go to Device tab
2. Open Accessibility settings
3. Under Mobility settings, tap Assistant Menu and make sure the feature is enabled
4. Now a new white rectangle icon appears and upon tapping, it lets you perform these actions: Menu, Open notification, Home, Back, Set volume, Lock screen, Restart, Power off, Capture screen, Zoom, Settings, Open Device Options (as if you press the power button), Recent apps, Rotate screen, and Set brightness
5. You can Edit, Add, Remove, or Re-order the quick access buttons