UV-Packer for Blender Add-on 1.00.00
UV-Packer for Blender is a free, fast and exact tool for automatic packing of UV islands. It is a one-click answer to the laborious work of sorting and compressing unwrapped polygons into UV sheets.
Installation
In Blender, open the add-ons section in preferences:
Edit -> Preferences -> Add-ons
Use the install button and select the add-on zip file you downloaded.
This will install the addon but not enable it. It will now show up in the list of installed add-ons. Use the enable checkbox to enable the UV-Packer add-on.
UV-Packer for Blender consists of 2 components that need to be installed separately: The UV-Packer for Blender addon that provides the user interface in Blender and the corresponding program that performs the packing. You can find the second component for free at https://www.uv-packer.com/blender
Please check the README for further details.