Scrivener - Scrivener is a content-generation tool for composing and structuring documents.
draw.io - Online diagramming application
Manuskript - Open-source tool for writers.
LucidChart - LucidChart is the missing link in online productivity suites. LucidChart allows users to create, collaborate on, and publish attractive flowcharts and other diagrams from a web browser.
FocusWriter - FocusWriter is a fullscreen, distraction-free word processor designed to immerse you as much as...
PlantUML - PlantUML is an open-source tool that uses simple textual descriptions to draw UML diagrams.