HyperSpin - HyperSpin is an animated arcade frontend for Windows for use on Home Arcade Machines.
Mitch - The unofficial mobile app for itch.io
LaunchBox - LaunchBox is a portable, box-art-based games database and launcher for DOSBox, emulators, arcade cabinets, and PC Games. Download it free!
GameDatum.com - A platfrom of free online games. A list of all the available online free games from various producers online.
OfflineList - A widely-used, multi-platform ROM manager.
ScienceGameCenter - The goal of the Science Game Center is to demonstrate to teachers, scientists, museums, and parents the myriad ways games can be used to improve education in math and science.