Joplin - Joplin is a free, open source note taking and to-do application, which can handle a large number of notes organised into notebooks. The notes are searchable, tagged and modified either from the applications directly or from your own text editor.

pdf.to.design - Effortlessly convert any PDF document into Figma designs.

Sketch2PDF - Export, merge & optimize PDF files in Sketch

Chat with PDF - Chat freely with PDFs – without limits or login

Kaleidoscope - Easily spot the differences in text and image files. Review changes in seconds with the world's most advanced iOS and Mac diff tool.

PDFGPT.IO - Simplify PDFs with chat.