Wikipedia
Lucidchart
Lucidchart is a web-based diagramming software which allows users to collaborate and work together in real time to create flowcharts, organisational charts, website wireframes, UML designs, mind maps, software prototypes, and many other diagram types. Built on web standards such as HTML5 and JavaScript, Lucidchart is supported in all modern web browsers like Google Chrome, Firefox, Safari, Microsoft Edge and Internet Explorer 8+.