The usage of this addon is simple, in any node editor, go to the nodeTreeStore panel

1. select the nodes you want to save

2. Click Save and name it

3. You can see your node tree in the list and you can load it back to the node editor in any project.

4. You can also use the copy-paste function to move your node trees across different blender project.

NodeTreeStore also automatically back up 

1. Image resources used in the node tree.

2. Material referenced by the node.

3. Empty Object referenced by the node. (location, roation and position of the object)

You can set the "store path" of the addon in preferences, the add-on will save and read from that path. Addon will not delete any resources even if you uninstall it.