SaaS 1000 - Free exportable list of the fastest growing SaaS companies
draw.io - Online diagramming application
Look at that SaaS - Inspiration and resources for SaaS founders
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.
Inside SaaS Sales - 1000+ sales emails and voicemails from top SaaS companies
PlantUML - PlantUML is an open-source tool that uses simple textual descriptions to draw UML diagrams.