The creative people at Makers Valladolid designed some fun STEMFIE projects you can download from their GitHub page. Check out the video of the crawling and the pushing robot.
STEMFIE Projects by Makers Valladolid
The free and never-ending 3D-printable educational construction-set toy you can download and make at home!
This toy is unsuitable for children under three years due to choking hazards! 
