While older versions were entirely free, the current "JointPushPull Interactive" requires a small one-time fee for a perpetual license. However, a free trial is usually available to test the features. Tips for Beginners
The Ultimate Guide to Joint Push Pull SketchUp Plugin: Free Download and Pro Tips Joint Push Pull Sketchup Plugin Free Download
Moves faces along a specific axis (X, Y, or Z). While older versions were entirely free, the current