working with templates is good but their numbers should be increase i suggest working on the chat messenger boost its ui lovely landing page though!! ;)
I like working with its panel
Conceptboard - Instant Whiteboards for Teams & Projects
Diagrams for Mac - A diagram editor for visualizing structures and processes
Whiteboard Fox - Simple Online Whiteboard
Diagrammm - Fundamentals on data visualization
OpenBoard - The OpenBoard software is an interactive white board software.
Wireflow - Create beautiful flowcharts