GMADgui by REDUXsoftware
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GMADgui v.1.2.1
An easy way to compress/extract .gma files for Garry's Mod.
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GMADgui Features
Extract/Compress .gma files
Upload new .gma files to the Steam Workshop
Adding in a future update
View all listed addons in GarrysMod/addons folder
Adding in a future update