draw.io - Online diagramming application
The Jackbox Party Pack - The Jackbox Party Pack is a Trivia, Education, Co-op, Single and Multiplayer video game created and published by Jackbox Games Inc.
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.
The Vote's Out - The free phone party game with friends
PlantUML - PlantUML is an open-source tool that uses simple textual descriptions to draw UML diagrams.
AirConsole - A new way to play games together with friends.