I recently did a presentation to my internal team on "Animated User Interfaces - improving user experience with animation." It went very well and I wanted to share some of the great articles and resources I found. There are some really great examples of forms and checkout processes on a mobile device.

Animated Interface Articles

Invisible Animation

Transitional Interfaces

Animation Principles in UI Design: Understanding Easing

Smart Transitions In User Experience Design

Using Motion For User Experience On Apps And Websites

Redesigning the Login Screen

Payment and Checkout

Improve the payment experience with animations

God is in the details

Making a Difference with Animation

Google - Authentic Motion

Mass/Weight

CSS Library

Animate.css

Animation Resources

Animation & UX Resources