Here is the current version of the$16.95  ESP32 development board using an ESP-WROOM-32 module directly from Espressif.   My optimism about the availability of the ESP32S modules from AI-Thinker was misplaced.  I believe they are finally shipping now but since I haven’t seen any with my own eyes I remain unconvinced.  In the meantime, I switched to a module that is actually available in production quantities.

Top View of New PCB

The ESP32 board has a Espressif WROOM-32 module installed with the pinout marked on the PCB albeit in very small letters.    The PCB is routed out under the antenna for the best RF performance.  The WROOM-32 module is certified worldwide by the relevant authorities and has an FCC Id number.

http://www.ezsbc.com/index.php/products/wifi01-28.html is where you can buy some for $16.95 each.  The schematic is also available for download and there are a few example programs on the forum.