Build a Better Mobile Input
This is such a handy tool for building forms! Choose different combinations of type, inputmode, and autocomplete attributes on input elements and see how that will be conveyed to users on iOS and Android devices.
Link tags: builder
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CodePen - CSS Grid Template Builder
Here’s a handy interface if you want to get your head around named areas in CSS Grid, also known as doing layout with ASCII art.
YUI: CSS Grid Builder
A handy tool for creating grids using Yahoo's CSS.