The CTU-NetTest mobile application of the Czech Telecommunication Office enables users to obtain information about the current quality of the mobile Internet access service. A mobile application is available for the Android and iOS operating systems. The main difference between the apps is the absence of a certified measurement mode within the iOS app. Established conditions for mobile certified measurement cannot be fulfilled on mobile phones and tablets with the iOS operating system – iOS applications are not allowed access to mobile network parameters within the operating system.