Easy parallelogram drawing for Newtonian mechanics.
This page here: http://www.ballooncalculus.org/mechanics
For encouraging similar diagrams freehand or with a set-square.
For helping get beyond vertical and horizontal decomposition… e.g. for parallel or perpendicular to an inclined plane.
Interactive but all in the browser - no uploading or downloading but you can load and save work.
Thanks for looking. Feedback welcome.