Alexschreyer is the developer of Flatten Faces Plugin for Sketchup. The plugin is compatible with SketchUp 8, SketchUp 2013.
With Flatten Faces Plugin for Sketchup, the users will be able to place randomly-oriented faces flat on the ground. This plugin is very useful for generating cutouts, like CNC-prep etc. The sketchup users can apply it with any solo face as well several, coplanar faces. It is also compatible with an unfold tool to flatten shapes.
How to apply it:-
In order to obtain the flatten faces menu, opt for one or more coplanar faces in your model and just right-click on them. Under this method, all the chosen faces will be grouped. But remember one thing, the original geometry should not be grouped.
In order to set up it smoothly, surf it from inside SketchUp (2013 or newer) and install it directly. For getting more updates, visit http://www.alexschreyer.net This plugin can be also accessed from GitHub