A single repository for open sharing of custom functions I have found to be useful generally.

The whole project can be cloned as a single Google Apps Script project, or instead individual functions copied as per requirements.

The Addon.gs script is there as this will install a menu that allows the functions to be installed and then applied across a whole GSuite domain if required. Custom Functions will only be available in a Google Sheet after the menu item has been selected once fromt hat sheet.