Me3 - Easily make new friends as an adult
draw.io - Online diagramming application
FriendZone - Make new friends based on your interests and hobbies
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.
Revaise - Do peer reviews right on Revaise.
PlantUML - PlantUML is an open-source tool that uses simple textual descriptions to draw UML diagrams.