Google Lens - Discover information about something by taking a photo
Greenshot - Greenshot is a free and open source screenshot tool that allows annotation and highlighting using the built-in image editor.
GImageReader - gImageReader is a simple Gtk/Qt front-end to the Tesseract OCR Engine.
ShareX - ShareX is a free and open source program that lets you capture or record any area of your screen...
OpenScan - FOSS Document Scanner
LightShot - The fastest way to take a customizable screenshot.