I swear by this free app for adding notes to PDFs

The app easily edits PDFs whether through annotations or direct file editing. It works with text, images, and graphics, and ...
XDA Developers on MSN

This lightweight note-taking app is the perfect companion to NotebookLM

The successful pairing of Zettlr and NotebookLM is about creating workflow harmony. NotebookLM acts as your intelligent ...