This add-on is released under the GNU General Public License (GPL). The source code for "Pencil+ 4 Line for Blender" is available on its GitHub Page. It can be downloaded, reproduced, distributed and modified according to the GPL. However, please understand that we cannot answer questions about the contents of the source code.

Pencil+ 4 Line for Blender GitHub Page

Please refer to the following page for details about the GPL.