diff --git a/README.md b/README.md
index 0a0de11..7ad72ee 100644
--- a/README.md
+++ b/README.md
@@ -356,6 +356,7 @@ Here are complete firmwares to turn them into MQTT-controlled smart home nodes:
 * [kobold2mqtt](https://github.com/krambox/kobold2mqtt) - Bridge between Vorwerk Kobold Vr200 internet gateway and MQTT.
 * [leaf-python-mqtt](https://github.com/glynhudson/leaf-python-mqtt) - Extract data from Nissan Leaf API and post to MQTT.
 * [miflora-mqtt-daemon](https://github.com/ThomDietrich/miflora-mqtt-daemon) - Linux service to send Xiaomi Mi Flora plant sensor data to an MQTT broker.
+* [MQTT.Cool](https://mqtt.cool) - A web gateway that optimizes any MQTT broker when sending real-time data to web clients with automatic throttling.
 * [mqtt2ble](https://github.com/hardillb/mqtt2ble) - A way to bridge MQTT topics to BLE Gatt characteristics.
 * [mqttclpro](https://github.com/dc297/mqttclpro) - MQTT Client with tasker integration Android app.
 * [mqttDB](https://github.com/hobbyquaker/mqttDB) - A JSON store with MQTT interface.
@@ -382,6 +383,7 @@ Here are complete firmwares to turn them into MQTT-controlled smart home nodes:
 * [MMM-mqtt](https://github.com/javiergayala/MMM-mqtt) - This is an extension for the MagicMirror². It provides the ability to subscribe to MQTT topics and display them.
 * [MQTT Dash](https://play.google.com/store/apps/details?id=net.routix.mqttdash&hl=de) - Android App: With the app you can create dashboards for your MQTT enabled IoT Smart Home devices and applications.
 * [MQTT-Hyperdash](https://github.com/kollokollo/MQTT-Hyperdash) - A universal independent MQTT Dashboard for linux/Raspberry Pi.
+* [MQTT.Cool Test Client](https://testclient-cloud.mqtt.cool) - A web interface for testing interaction between MQTT.Cool and any MQTT broker.
 * [mqtt-panel](https://github.com/fabaff/mqtt-panel) - A web interface for MQTT.
 * [mqtt-svg-dash](https://github.com/jpmens/mqtt-svg-dash) - Subscribe to MQTT, extract JSON from a message and make lights blink on an SVG page.
 * [mqtt2highcharts](https://github.com/matbor/mqtt2highcharts) - Plotting live numbered data from a subscribed MQTT topic using Highcharts.