Please use my Discord server to report any issues which you may encounter with this addon; if you have Discord open, an option to join the server should appear in the main window.
This addon is a simple one: it allows you to leave your current group by way of a single slash command, instead of right-clicking your character portrait. It is much faster and more convenient, saving precious seconds which could be used more productively (somehow). It should work with both the Classic and Retail versions of the game.
With the addon enabled, simply use /lp, /ql, /qp, /lf or /qf to leave your current group.