Sofi (a Simple Organisational File Indexer) is an open source (GPLv3) moodboard app for PC built using Electron and Node.js, running entirely locally on your own machine. It is a fork of the Moodbored app created by Nathan Wentworth, with an effort to simplify the original codebase and make the program a lot faster.
Usage is as simple as dragging and dropping files to create different project boards.
Download for Windows
Browse the source code on Gitlab