InVision Studio - The world’s most powerful screen design tool
draw.io - Online diagramming application
Appsee - Appsee’s qualitative app analytics lets you watch user session recordings and touch heatmaps for every screen, supplying you with a deeper understanding of user behavior and performance issues.
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.
Skaffolder - Cloud platform for React, Angular JAVA, Node JS, Go & PHP web developers
PlantUML - PlantUML is an open-source tool that uses simple textual descriptions to draw UML diagrams.