Lightweight Spigot menu GUI library supporting multiple versions.
GUILib is a library that enable easy creation of GUI Menus in-game (for example, the server selector menu for your minigames lobby).
As of right now, this plugin has been tested on PaperSpigot 1.8.8. Although not guaranteed, it should work on higher versions.
GUILib is designed to be a dependency and library for plugin developers to use, and without another plugin hooking into it its functions are extremely limited.
Documentation is available on
https://github.com/KuromeSama6/GUILib/wiki.
If you are looking for something like a menu for your lobby or minigames selector, there are tons of other plugins on Spigot that requires no coding.