Sketchup 2016 required some modifying to get this to work (Windows 7). This loader would not run for me. To fix, I had to first install this extension from the warehouse. Next, I had to install the rotated box and cylinder tools from the warehouse. Third, I had to rename/delete the .rb files in the 3Pts_Tools folder and replace them w/ the installed copies from my plugins folder. Those copies do NOT have the same name(3Pts_Tools puts a 'M' on the end of the file names) so you have to make sure you name the .rb's w/ that M on the end or edit the loader .rb to reflect the lack of an 'M' in the file name. Restart sketchup and the toolbar should appear.
This set of steps will suffice until a new package w/ the up-to-date .rb's is posted. I did NOT attempt to do rotated rectangle as sketchup comes with that tool built in as of Sketchup 2015.