TinEye - Reverse Image Search to help find an image's source, duplicates or altered versions.
Haystack Search - Haystack helps you make the most of your time, by searching all your files and documents in the cloud in one place. It's been built for privacy from the ground up, so your data isn't stored on a server, just your computer.
GImageReader - gImageReader is a simple Gtk/Qt front-end to the Tesseract OCR Engine.
MailJack+ - Send PDFs as postal mail
Microsoft Lens - Microsoft Lens (formerly known as Office Lens) is an all-in-one application designed for Windows, Android, and Apple devices, allowing you to capture important information from signs, PDFs, whiteboards, and more to add.
Paperkit - Create and download custom graph, lined, or dot grid paper