draw.io - Online diagramming application
Jibility - Business architecture software for capability-based roadmaps — the simple tool for translating strategy to execution
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.
productboard - Beautiful and powerful product management.
PlantUML - PlantUML is an open-source tool that uses simple textual descriptions to draw UML diagrams.
Aha - Aha! is the new way to create visual product roadmaps. Web-based product management tools and roadmapping software for agile product managers.