I (Richard) use a UniDesk®, US Patent Reg. No. 3,826,031, July 27, 2010, I invented and designed for holding up heavy books to read, described on the The UniDesk™ page of this website, which you can access by clicking above.
The US patent drawings and application for the UniDesk were drawn, written, and executed by my son, a high school physics and earth sciences teacher, and a professional inventor, and the inventor of Reptangles™, a toy system comprising twenty-four pieces of plastic in several colors poured and molded in China that look like turtles that assemble into geometric shapes, puzzles, and symmetrical structures. The pieces and constructions flip, slide, and turn in what are known as "geometric transformations", an essential part of our National Math Standards.
A biochemistry major at Rice University in 2003, my son hatched his Reptangles idea while taking an elective art class during the spring semester of his junior year.
His registered patented and trademarked geometry invention is licensed to, manufactured, packaged, and distributed by the Fat Brain Toy Company. You can find Reptangles™ by typing Reptangles into Google or any Internet browser, or by clicking here, https://www.fatbraintoys.com/toy_companies/fat_brain_toy_co/reptangles.cfm.
A box of Reptangles™ includes an eighteen-page Reptangles Exploration Guide, written and designed by my son, containing 237 informative multi-colored illustrations showing how to play with and assemble the pieces, and interpret the results. While the system is called a toy, and will entertain and fuel the imagination and thinking skills of children, it will challenge the conceptual and visual-spatial abilities of any adult. The system requires the use of imagination—the pieces look like turtles—but there is nothing new or fake about the immortal geometric shapes they represent when assembled and brought to life.
A lasting practical value for children (and adults) playing with and using this toy/system in their homes is that it causes them to learn the names of geometric shapes they have never heard of, which never change, and learn how to recognize them in three-dimensional space, as it also causes them to visualize manipulating geometric objects in spatial dimensions using logical thought. The system pieces, box, and learning guide cost about twenty-seven dollars.
To watch and listen to a video that will cause you to see in detail how the Reptangles™system works, narrated and demonstrated by George Stephanopoulos on ABC's Good Morning America, click here, https://www.fatbraintoys.com/toy_companies/fat_brain_toy_co/reptangles.cfm.
For a detailed story about how this Reptangle entrepreneurial venture happened over time, read a case titled The Toytle Company, published in Business Voyages: Mental Maps, Scripts, Schemata, and Tools for Discovering and Co-Constructing Your Own Business Worlds, Case 9, page 323, by clicking here: https://www.amazon.com/Business-Voyages-Schemata-Discovering-Co-Constructing/dp/1413480810.