Write text, get a flow chart, a sequence diagram, a pie chart... The chart is inserted in your document or slide, and you can edit its text again afterward.

TIPS : 
- Use mermaid.live for bigger diagrams. This addon is made to maintain many small diagrams, not to generate giant ones.  
- Don't try to add icons, they won't work
- if your graph is very big use https://mermaid.live instead
- Keep the graph positioned in-line in your document, otherwise you won't be able to edit
- If you are logged in with multiple google accounts, this will only work with the "main" one
- all the mermaid charts should be supported, I update mermaid to the latest version from time to time
- if this app has any issue, your work isn't lost. Do a right click / "alt text" on a chart to see the mermaid source code, then edit your graph in https://mermaid.live 
- people without the add-on see the graphs, but cannot change their content.
- This uses mermaid 11.12.1 for rendering : https://mermaid.js.org
- there's a similar addon called "PlantUML Gizmo" that works in slide too, but uses a different rendering system and syntax, give it a try

This is ideal for technical documentation, where having up to dates graphs is more important than having pretty graphs. Only editing a few words here and there is very easy with this add-on.

Please keep in mind that this add-on is provided for free, I'm not making any money with it. Feel free to leave a review for this add-on so that more people get to use it. Reviews really motivate me to improve the add-on. 

The graphs are generated client side on your machine. The mermaid code and generated images are only seen by Google Docs and you, i don't even have access myself. There is no telemetry in this add-on. The code is open source and can be read on Github.