This is a discussion topic for the Ore project, VirtualChest. View the full project on Ore for downloads and more information.
VirtualChest is a sponge plugin which provides virtual chest GUIs for menus like ChestCommands.
An example GUI:
The development of the plugin is based on sponge api 7.1.0, and additionally considers the support of api 5.2.0, so it is expected to work normally on spongevanilla/spongeforge 1.10.2, 1.11.2, and 1.12.2 servers.
There are some example GUI configurations which you can copy and edit for your custom GUI menus, and they will be extracted when the plugin is loaded.
VirtualChest uses bStats to anonymously collect usage data, and it can be disabled by editing
config/bstats/config.conf. All the collected data can be found here: https://bstats.org/plugin/sponge/VirtualChest
This plugin is licensed under LGPL 3.0 license, and you can spread it to almost anywhere applicable to LGPL license without having to manually request for my agreement. There are only two places which need to be noticed: mcbbs (a Minecraft forum in China, http://www.mcbbs.net/), and here. The only reason is that I have already posted the plugin there, and the repost is not welcomed by forums.