1. A mobile data processing device, comprising: a memory system for storing program code instructions and data; a processing system comprising at least one processing unit, wherein the processing system is configured to execute at least some of the program code instructions and to process the data stored in the memory system; and a detector system for detecting at least one type of environmental identifier from a current environment of the mobile data processing device, wherein: the memory system comprises at least one application executable by the processing system wherein the at least one application contains a set of functions executable by the processing system; the memory system further comprises one or more plugins, wherein the at least one application and the one or more plugins are installable separately from each other, and wherein at least one of the one or more plugins at a time is selectable as a currently active plugin for the at least one application; if a user interface element selected by the user corresponds to multiple plugin, the highest ranking plugin is selected to be at least the currently active plugin; and the at least one currently active plugin does not comprise executable functions but is configured to define operations of the mobile data processing device during execution of the at least one application, wherein the operations defined by the currently active plugin comprise one or more tasks, wherein at least one of the tasks: is configured to call a subset of the functions contained in the at least one application, wherein the subset of functions is equal or smaller than the set of functions and wherein the subset of functions comprises at least one function for operating the detector system; and defines an order of execution for the subset of functions.