Synfig Studio: https://www.synfig.org/
Wick Editor: http://wickeditor.com/
Tupi 2D Magic: http://www.maefloresta.com/portal/ind...
Animation Desk: https://www.kdanmobile.com/en/animati...
iMotion HD: http://fingerlab.net/portfolio/imotion
Pivot Animator: http://pivotanimator.net/
Vectorian Giotto: http://www.tucows.com/preview/501883/...
OpenToonz: https://opentoonz.github.io/e/
Krita: https://krita.org/en/
Rough Animator: http://www.roughanimator.com/
Pencil 2D: https://www.pencil2d.org/
StickNodes: http://sticknodes.com/
Toonator: http://toonator.com/draw/