This would make a cool Dolphin Module

https://www.draw.io/

The source code: https://github.com/jgraph/draw.io

Not much use for this on those creepy dating sites everyone's building, but could be quite useful on some business sites. 

and what features do you expect from this module?

 I like that! 

That could be very good on technical sites.

Damn you for posting that link - I just spent my last 40 minutes messing with it. It's blimmin addictive too.

Thanks.

I like it :D

Why not just do this?

http://webcamyourface.com/page/graph_tools

 RE:

 The app currently interfaces with Google drive to store drawings, but for a dolphin module I believe it must be provisioned to store drawings on your own server in a designated folder such as /drawings.  Once a user creates a drawing and save it, their own unique sub folder should be created to store the drawing that corresponds to their user ID, ie drawings/1, drawings/2, etc.  Stored drawings would have to be tied into privacy settings somehow.  Overall, I suppose it should work much like the files module does, only with a view/edit page. 

That would be the most basic requirements.  As the module evolved, other capabilities would be useful:

• The ability to send drawings via site email.
• More refined privacy controls to assign edit privileges to (public, members, friends, me only)
• The ability to add drawings to "Featured Drawings"
• Export to jpg
• Additional symbol libraries for typical applications (electronic schematic symbols, architectural, landscaping, etc.)
• A symbol editor to create your own symbol libraries.

I'm sure other features will come to mind, for anyone that may find this useful,

Not necessarily true. You could use it to make a Flow Chart of all the people you've dated. LOL

 Yeah... it's easy to get mxGraph apps into a Dolphin page.... but then what?

 save the file and share, print, mail or whatever... why take the chance on a database filling up with useless drawings.

Besides, no argument here. Just showing what other options are.

If you are thinking of a collaboration site, then you might want the drawings on the site available at all times.

 RE:

 I think I said that, when I mentioned onsite storage with privacy settings.  It occurs to me that this would also be useful as a group mod, where diagrams created with the app could be used to convey and share ideas amongst "Fans".