Uxpressia - Create customer journey maps, personas & impact maps online
Dia - Dia is a GTK+ based diagram creation program for GNU/Linux, MacOS X, Unix, and Windows, and is released under the GPL license.
Smaply - Online tool for customer journey maps, personas and stakeholder maps. Try for free. Best hub for customer experience insights. Great customer support.
draw.io - Online diagramming application
Journify Now - JOURNIFY - AI-powered collaborative customer journey mapping and analytics platform for every product team member, from idea to scale
yEd - yEd is a free desktop application to quickly create, import, edit, and automatically arrange diagrams. It runs on Windows, Mac OS X, and Unix/Linux.