This website was originally part of Yi-Ting Tu (Rick Tu)'s personal website. However, as Ray Optics Simulation became a more and more non-personal project, and due to future consideration of new projects with some contributors, the original ricktu288.github.io was split into yitingtu.com and phydemo.app in December 2022, where the former is Yi-Ting Tu's new personal website.
This website, still managed by Yi-Ting Tu, is intended for physics educational projects, including physics "demos" (instructions, videos, interactive images, etc., to show the physics directly), and physics "apps" (computer programs for users to build physical systems virtually, and to simulate them). However, due to the very limited spare time of the author, it is likely that no new projects will appear here for years.