AppMockUp - Create the most compelling screenshots for your app.
OpenToonz - OpenToonz is an animation program that is a free software version of Toonz, the animation software...
Placeit - Generate realistic product shots in seconds
Adobe Animate - Adobe Animate is a Flash, vector animation software.
Smartmockups - Create stunning product mockups, easily and online.
Synfig Studio - Just another WordPress site