Spirit - The animation tool for the web.
OpenToonz - OpenToonz is an animation program that is a free software version of Toonz, the animation software...
Lottie by Airbnb - Easily add high-quality animation to any native app
Synfig Studio - Just another WordPress site
Haiku Animator - Create powerful animations for any app or website
Adobe Animate - Adobe Animate is a Flash, vector animation software.