What can be said about Drawpile? A little known original program. It lets people draw over the internet on the same canvas. Really easy to overlook but having counted hundreds of persons who 'wish they could draw' it's a shoo-in. Drawing socially can be an avid means of getting better. It's obviously not a promise, most people never stick with art though that's not important. All that matters is fun and drawpile has loads of that. Wether it's role play, witches or what ever. With easy access there's plenty for adults and kids, like a theme park ride. Having been a heavy drawer since being able to hold a pencil it's easy to recommend. I've always wished to be able to draw reliably over the web and thanks to this little gem it's now a daily thing. With an active creator (Calle Laakkonen) and being completely open source (free) it's a mix well worth mentioning.
It's also worth mentioning the learning curve is not that steep. A fairly simple toolset though there are some wiz kids here and there. If interested in drawing or looking to diversify give this one a try.
p.s - There are NSFW servers - just a heads up. Yay porn
Why are you my flagger?