One click to import what you want from a selected source file to your current InDesign document (or all opened documents or files in a folder).

Import what you want (paragraph and character styles, object styles, swatches, master pages, table and cells styles) from selected source file to the current InDesign document.

You can also duplicate a layer from the source document to the target document(s).

Mentioned by Stefano Bernardi at Redokun’s post about Must-Have InDesign scripts (#97).