The theme
Blocks kit theme is a blank canvas onto which you can drag blocks. The theme has all the files need for the blocks library pre-installed, allowing you to get making faster. You can always add the blocks to other themes, but the blocks kit theme is an easy way to get started.
The theme has a few general options like, page colour, font size, font type, header size, line height, page alignment, background image and width. Elements like the header and sidebar have been removed to allow you freedom to create them the way you would like them (if you would like them at all).
The theme is used on this site.
Using with 3rd party themes
A number of files and snippets are included to make Blockkit work with 3rd party themes. Activating Blockkit on a 3rd party theme is as easy as dragging a snippet into the page header. (for more info see the support section)
A popular 3rd party theme is Jonas's Blocks Box theme specifically designed to be used with the Blocks plugin and Block Kit. A discount code of 3.25 euro towards the Blocks Box theme is provided with Blockkit.