The ESP32 is the ESP8266 successor. The ESP32 is loaded with lots of new features. It combines Wi-Fi, Bluetooth wireless capabilities and the dual-core processor.
The ESP32 comes as a standalone module or as a full-featured development board. There are lots of ESP32 development boards available. Select the one which fits your needs.
Official DOIT ESP32 Development Board
The entire solution takes up the least amount of printed circuit board area.
This board is used with 2.4 GHz dual-mode Wi-Fi and Bluetooth chips by TSMC
MH-ET LIVE D1 mini ESP32
TTGO T-Energy ESP32 8MByte Module + 18650 Battery
ESP32 + OLED
TTGO T-Camera ESP32 Module + 0.96 OLED + PIR sensor
TTGO T5 V2.3 WiFi ESP-32 ePaper display