MQTT Snooper is a free Android-based program developed by Maxime Carrier in the Utilities & Tools category. It is a comprehensive MQTT client that comes with a plethora of features. The program allows you to subscribe and unsubscribe to multiple topics with a single click and also provides a publication filter. If the payload is not in UTF8 format, the program displays the publication in hexadecimal. Additionally, it allows you to save a publication payload to a file and publish from a file.

MQTT Snooper also automatically detects image publications (PNG, GIF, JPEG) and displays a thumbnail. It supports multiple configurations for connection and offers various functions related to publication, such as deleting one or all publications on one level, copying payload, and viewing payload in hexadecimal. The program can publish in hexadecimal/utf-8 and run as a service, enabling it to receive publications while in the background. It also provides basic statistics, such as total payload and message received, and supports notification on topic change. The program also supports basic secure connection (no client certificate) and IPv6. In conclusion, MQTT Snooper is a feature-rich program that offers a wide range of functionalities.