This is a Google AI product that can converse with you about any document you upload to it, and can convert any complicated document you upload to something simpler.

AI research assistant with access to peer-reviewed articles! Works with Zotero. 

Upload any PDF and ask it questions or ask it to analyse the text.

Generous free plan for document conversations. Can upload PDFs, PPTs, TXT, CVS files, and more. Web plugin works with Google Drive or Zotero.

Great tool for quick interactions with documents, and includes a feature to share the document with others via a link.

Skip through long technical documents and have Humata analyse it for you.  Like Chat GPT but for PDFs. Free for 60 pages, and 2€ a month for educators.