The paper deals with designing and implementation of a probe that measures the quality of Sigfox radio network coverage. This probe consists of the mobile application for Android operation system, Sigfox RF module, and Bluetooth module. Finding the coverage quality is solved by wireless communication between mobile device and Sigfox module, which sends Sigfox message. The developed solution mainly offers a possibility to display base stations on a map and show a list of all measurements. The probe represents a tool, which is intended primarily to find areas with weak or non-existent Sigfox network coverage and as the authors know, the presented solution is unique so far.