UX Archive Animated - iOS apps animated user flows
Marionette Studio - Marionette Studio is an online animation software for beginners and professionals. Animate 2D characters and environments in minutes with no prior skills.
UI Patterns - Level up with interactive mobile design patterns
Lottie by Airbnb - Easily add high-quality animation to any native app
Mobbin - Latest mobile design patterns & elements library
CSS Animation Cheat Sheet - Awesome CSS3 plugin for spiffy animations