Noticed this today (but been around since february apparently),
and had a quick play - very easy to use.
https://www.gumstix.com/blog/build-your ... -in-a-day/
It's a web based drag and drop interface to add and layout components.
There's already a few sample designs to work with:
Pricing seems to be $1999 design fee then around $25 per unit (no minimum)
Compares well to element14's custom pi service with minmum order or 5000 units