PDFgear is an AI PDF editor that allows you to edit, annotate, convert, sign, and summarize PDFs through intuitive natural language commands. It features an AI summarizer for distilling crucial information, a smart proofreader, language translation, a text rewriter, and even a PDF copilot for chatting with your documents. You can download PDFgear for free over on their website, though keep in mind that it currently only has a Windows version available.