Classy icons crafted according to Microsoft guidelines. Available in PNG and SVG. Free for a link
Feather Icons - Simply beautiful open source icons
Lottie by Airbnb - Easily add high-quality animation to any native app
IconStore - Free icon packs by first-class designers
Marionette Studio - Marionette Studio is an online animation software for beginners and professionals. Animate 2D characters and environments in minutes with no prior skills.
Flat Icons - 20,000 unique, customizable icons with free lifetime updates
Spirit - The animation tool for the web.