The new blender viewport i so amazing. i'am trying a raindrop shader fully procedural, using panner and UV distortion. hope and enjoy blend file https://drive.google.com/open?id=16fhoAQy4bhkjkVP6cCWU2WYnNL-kg9SS
Eevee Raindrop shader
the base roughness i'ts a simple noise texture.
To make top drop effect i use a Voronoi texture with color ramp and Panning the Z location in Mapping node.
the side drops is a other voronoi texture with ramps and Panning effect.
The side Drops have a UV distortion to make a more natural flow.
Combine the graphs