ESP8266-based IOT Development Boards
Wio Node is an ESP8266 module for any IOT platform that is small and compact but very effective.
The Wio Core is a wifi module with an embedded ESP8266,developed from the ESP-WROOM-O2 for all IoT appllications.
SparkFun Blynk Board - ESP8266 is a light weight,interactive board monitored by a Blynk App.
ESP8266 WiFi Module acts an interface between the microcontroller board and your Wifi network.
SparkFun ESP8266 WiFi Shield provides the wireless connectivity that is required by the Arduino.
The SparkFun ESP8266 Thing is a combination of Wifi and the ESP8266 which has Iot applications.
Protocentral ESP8266 Wifi shield is the most suitable Wifi module for your Arduino.
Kalam V2 =Arduino+ESP8266 in one single board for Iot apps like home automation.