NAPS2 - NAPS2 is a document scanning application with a focus on simplicity and ease of use.
Mailspring - Mailspring is a mail client for Mac, Windows and Linux.
Simple Scan - Project information. Part of: The Gnome Project. Maintainer: Simple Scan Development Team. Driver: Simple Scan Development Team. Licence: GNU GPL v3.
Geary - Geary is an email application built for GNOME 3.
VueScan - Third-party software for film scanners and flatbed scanners.
Airmail - Airmail is a lightweight and lightning fast mail client for Mac.