Just reach out to me on Blender Market via the 'Ask a Question button on the right side of the product page. Thanks

To install the add-on, just open blender and go to the Blender preferences under the Edit tab. On the left is the add-ons or the get extensions section, You click the install from disc button on top and you go where you downloaded the addon. Save your preferences and you are good to go. The addon will appear in the N-panel Navigate to the Restore_State_V1.zip file (do not unzip) and install. Click the check box to enable the addon. The addon will be visible in the 3D viewport in the N-panel.