I was tired of adding custom classes to blocks and keep track of all my custom CSS. I searched on Google for some way to handle CSS for all blocks easily and I found this gem.
So simple idea and really useful!
I make reusable blocks and style them with this plugin, saves me so much time.
I can't explain how much this is useful plugin for me. styling a block without using such a plugin is something hard work but by using this we can change the style of any block easily.
This plugin will be more useful if you include a feature of auto-completing CSS or suggestion of CSS tags.
also if you add a button to copy style so that we can paste the same style in another block without wasting time on typing CSS again.