The Custom save plugin enhances Obsidian's save functionality by allowing users to add customizable callbacks to the save command. It provides an intuitive way to trigger additional actions whenever a save is performed, offering flexibility for workflows that require extra tasks during the saving process. Users can easily set it up by assigning the custom save command to their save hotkey and adding desired callbacks through the plugin's settings. This plugin is a powerful yet straightforward tool for improving productivity and customization in Obsidian.