Utilians is a Skript file that adds simple commands and has an extensive config. The script adds the following:
Gamemode Swapper (/gm, /gmc, /gms, /gma, /gmsp)
Broadcasting (/broadcast, with anonymous sending!)
System Messages (Join, Leave, Death, First Join)
Join MOTD + News
To edit the script config, open the script and scroll down to the "CONFIG" marker. Items marked with "opts." are options for the given module, "lang." is for text, and "perm." is for permissions.