Animated UIs can improve the UX. I said ‘can’.
“Animation, like any other facet of the web, must be designed. As web developers, we think about the effects of typography, layout, interaction, and shifting viewports, but when incorporating animation we have another factor to consider: time. It’s not just an extra aspect to consider, either: it increases the complexity of each of the aforementioned parameters exponentially. Rather than viewing this as a heavy mass of ideas, we can bake animation into the core of our user experience process to create dazzling, exciting, and engaging work that pushes boundaries and collectively elevates the medium of the web.”
(Sarah Drasner a.k.a. @sarah_edo ~ Smashing Magazine) ★