Screenshot Flow is a screen grab app that also generates clever user journey diagrams from screenshots to communicate with others about an app's design and workings. It is fully integrated with Google Drive and provides a diagram viewer online to keep stuff quick & easy. Diagrams are compatible with draw.io for almost limitless options for editing.
Arcentry makes it easy for backend and cloud specialists to plan and maintain complex server architectures.
It combines a feature-rich interface with a host of open-source, AWS, Azure and Google Cloud components to create interactive, fully 3D diagrams that can be exported as high-res images for presentations, blog posts and developer platforms.
scri.ch - draw anything. save. share. add ".PNG" to URL and save as image. slick.
Draw, Smile is a drawing app where your face is the interface. Draw a picture then smile as the command to your phone to save the image.
It's pretty fun.