Google launched a design in I/O conference on June 2014 guideline for Android Lollipop called Material Design. They created a visual language for users that must unify the experience across devices. Animations (motion, interaction & transitions) are a key part of the specifications.
Motion is extremely important for modern applications but be careful to not abuse of it. It have to be subtle and must have meaning to enhance the user experience (otherwise it could have the inverse effect).