This plugin allows players to double jump on Paper (including forks) servers and has tons of customization options.
/tdj [enabled/disabled] - Toggles double jumping
/tdj <username> [enabled/disabled] - Toggles double jumping for another player
/fly [enabled/disabled] - Allows you to fly
/fly <username> [enabled/disabled] - Allows you to set flight for another player
/groundpound - Allows you to toggle ground pounding
/djreload - Allows you to reload the configuration files
All pull requests are welcome. If you found a bug or would like a new feature added, contact me through the issues tab.