CellSource is a lightweight cross-platform Excel add-in for auditors and finance teams that lets you snip PDF excerpts into cells, store unbreakable evidence links in cell metadata, and generate one-click evidence reports — with AI-powered OCR and text-extraction enabling full-text and handwritten-search across embedded documents, instant highlighting/jump-to-page, and fast verification; everything is processed locally in your browser for privacy, making it a fast, Mac-friendly alternative to heavier, cloud-dependent audit tools.