Raspberry Pi foundation made a very surprising release of its new board, the surprise part is the price which is at just $5. I made a prototyping HAT for the Pi Zero with the same form factor. It has breakout for all the 40 pins, so all are accessible after soldering on the headers. Its available here.
Here are some pictures and a small video.
It is of the same size of the Pi Zero with matching holes with the main board for easy mounting. It also has ample of space making small prototypes. The proto holes are 0.1′ apart.