Every Monday, drawing aficionados across former Yugoslavia visit Twitter profile @crtkamo , which means “We doodle” in the closely related languages of Serbian, Bosnian and Croatian. On that day, the people behind this online drawing community post the doodle prompt for the week. Participants then start making and submitting their creations by tweeting under the hashtag #crtkamo .
Doodling topics have ranged from “something the size of a coin”  and “kilometer of hair”, to toys  and pirates , dream house , “a happy sky”  and summer , to David Bowie  and Professor Snape from the Harry Potter series . The participating artists use various techniques and styles and share each other's works.
“This is not a contest” is the main rule  of the game. Many of the images get re-tweeted by the main account, and that's the only reward provided by the organizers. Co-founder Zombijana Bones  explained in an interview:
Crtkamo postoji od 11. avgusta 2014.
Do sada smo imali 80 tema. Nedeljno dobijemo oko tridesetak radova (nekad više nekad manje).
Radi se o neprofitnoj inicijativi, gdje naš odabir zapravo nije nikakav sud da li je taj rad dobar ili ne, jer mi smatramo da su svi dobri.
“We doodle” has existed since August 11, 2014.
We have had 80 topics, so far. We receive about 30 works per week (sometimes more, sometimes less).
This is a nonprofit initiative, and our selection does not imply our value judgement about the works because we think they are all good.
Podgorica-born Zombijana  works as a designer and is a popular online artist in her own right, with 12,000 followers on Twitter and 67,000 likes on Facebook. Fans across the ex-Yugoslavia region have been ordering t-shirts with her illustrations of witty tweets , and in May 2014 she held an exhibition at the POINT Conference in Sarajevo , selling original works to raise money for victims of the terrible flooding  that year.
The “We doodle” project started as collaboration between Zombijana and freelance artist Živko Kondić . When he withdrew due to lack of time in November 2014, the most active member, Aleksandra Tosman  from Belgrade, replaced him in running the initiative. The duo have not missed a week since, alternating as agenda-setters and curators. They use the project to support humanitarian causes, and sometimes they provide bonus presents such as books or cinema tickets for participants. However, the primary goal of everyone involved is “to have fun and bring more art to the Internet.”
All you need to join #crtkamo  is a will to draw. Full disclosure: Both my young son  and myself  have participated in “We doodle”, and from experience I can tell you that any tool that enables you to express yourself visually will do, be it a pencil and notebook, post-it note, digital camera, scanner, or painting software.