Aseprite
Used by 9 peopleaseprite.org ↗

“For drawing I mostly use Aseprite, some custom tools, and Clover Paint on the Wacom tablet.”
Michael Brough Interview, Game developer, potion brewer · via Uses This 
“The animation engine is terrible and unreliable, so I've been trying out Aseprite for pixel art and animation.”
Dominik Johann Interview, Designer and illustrator, Crows Crows Crows · via Uses This