Learning to use this tool will help when it comes to changing and modifying firmware to improve its look and possibly performance. You may also be wanting to modify Android boxes you may be selling by adding a customised boot logo, this is made easy by the tools user interface.
This tool can be used on all Amlogic android firmware upto Android Marshmallow 6. Unfortunately Amlogic have discontinued development of Amlogic Customisation Tool and have made no plans to allow Amlogic Android 7 Nougat firmware to be used with this tool. In time Amlogic will no doubt release an updated version of this tool to allow further modifications of Android firmware.