Was wanting to put in the product flow for the application am building and did not see the flow chart option. Would be a great addition. Also if you can allow XML / CSS images, we can do the entire App flow on Coda itself.
welcome to Coda Community!
Currently there is no such feature (yet), but - if you are willing to spend some time with SVG - have a look at @Paul_Danyliuk post:
MEGA TRICK: SVG in Coda (one step away from generated charts and mind maps!).
Perhaps not the best plug-n-play solution, but really flexible to build your own implementation