Artdraw™ is a series of drawing applications for Scratch.
The original was created by KoopasRock (now known as ToadfanSchool) and sequels by various people.
Versions of Artdraw:
Artdraw™ 3 (WIP)
Artdraw™ Pixel (Unfinished)
Update: Artdraw™ 3's development stopped 3 years ago, but is now being worked on again! Be sure to check the newer versions out!