Today, I launched free online flow chart diagramming tool at https://flow.lakshmikanth.com
Initially, it was developed for internal use at ContactWise (and to extend functionalities of our no code platform).
During development, we realised that this can be stand-alone tool and can help architects, freelancers, developers to develop flows, mockups etc.
Here is the sample flow designed using the tool
I am planning to add AWS and Azure shapes to develop architecture diagrams in the next release.
Feel free to try at https://flow.lakshmikanth.com. Your feedback are most welcome.