Kawase blur effect
This is a faster version of the traditional "Blur" effect. It's recommended that you use this one rather than the "Gaussian" blur effect.
The Blur setting controls the strength of the blur, while Quality controls how smooth it looks (higher values look better but are more demanding). The Pixelize X and Pixelize Y settings can stretch the blur horizontally or vertically for a directional, motion-like blur.
Reference
All effects are listed in the effects reference page.