A ESP32 NodeMcu WiFi CP2102 Module with Built-in Antenna, MicroUSB Connector, Bluetooth BLE 4.2, Analog Digital Converter, GPIO with PWM Functions, 12C, SPI, Etc and Supports Remote Firmware Upgrade.

The ESP32-CAM is a WIFI + Bluetooth Development Card based on the ESP32 Chip, with the additional possibility of using a camera. It is ideal for a variety of loT applications.

Stem Shield for your Arduino, the Velleman.

An ESP8266 Wifi Shield for Arduino.

The motor shield is based on the L298 , it is a double complete bridge driver designed to drive inductive loads, such as relays, solenoids, DC and stepper motors. 

An Controller Module of XH-M603 Charge, very easy to use, learn more about it here at ElectroFun!

Gravity: IO Expansion Shield for Arduino V7.1

The HC-12 433MHz Transceiver is a wireless communication Module, which is based on the RF SI4463 chip, has a built-in microcontroller and can be configured by AT commands, the maximum output power is 100mW (20dBm) and the receiver sensitivity differs from: 117dBm to -100dBm, depending on the transmission speed. Accepts 3.2V - 5.5V and can be used with 3.3V and 5V UART voltage devices.

This version of the Ethernet Shield is not only compatible with Mega 1280 and 2560, but also provides a Micro SD card slot for read / write

Shield XBee SparkFun

Shield of relays for Arduino, with 2 channel mechanical relays and with 2 channel MOS switch , providing an easy way for applications low and high voltage control. 

WiDo is a WIFI IoT Node development board compatible with Arduino.

Do you want to program your RGB LED strip to be a little more "rhythmic" or "unpredictable"? This RGB LED Strip Shield contains all the necessary components to create a super cool RGB LED project with your Arduino.

This ENC28J60 RJ45 Ethernet Shield is ideal for enabling your Arduino Nano with an Internet connection.

The upgraded Input Shield for Arduino includes a two-axis mini-joystick (with moment switch) as well as four colored buttons (red, yellow, blue, green). The reserved interface of the APC220 Radio Data Module (SKU: TEL0005) and the Xbee interface are designed to make it easy to perform the wireless remote control button controller. The shield can easily be stacked on top of your Arduino boards. It can also connect with OLED2864 and OLED9664.