Very interesting! A tiny development board smaller than a thumb with a built-in OLED full color display, ESP32 SoC, Wi-Fi, 512K of RAM, USB Type C, built-in lithium-ion battery charge/discharge, programmable on Arduino IDE, and $5 when bought in quantity. Introducing the TTGO. Alas, there are multiple different variants of this development board, those features must be only of the newest once. These are some of the other development boards I could find.
20191021/DuckDuckGo TTGO
20191021/DuckDuckGo TTGO $5
20191021/DuckDuckGo TTGO $5 OLED
20191021/DuckDuckGo TTGO $5 color OLED
20191021/https://www.cnx-software.com/2017/10/13/this-ttgo-board-combines-esp32-lora-radio-and-oled-display-for-just-10/