8. A system for task modeling interactive sequential applications for one or more mobile devices, comprising: a) a central processing unit (CPU) having a software tool for defining a generic meta-model of the target applications, wherein said generic meta-model consists of a static model of application components, and a dynamic model of identifiers of application screens and connections that are based on an inheritance mechanism whereby model entities having a parent-child relationship are reusable in different models; b) a passive Task Model database, being in data communication with said CPU, for storing said generic meta-model for future reuse, which further comprises static instances of the generic meta-model specifically generated for a variety of mobile devices; c) a tracker module in said processing unit for: c1) real-time tracking and monitoring user's actions during user-system interactions and creating a screen unique identifier for each application's screen visited by the user of said mobile device by choosing an identifier that matches a signature of each application's screen, wherein created identifiers are used for generating active models of the user's actual usage; and c2) generating a unique identifier for each captured screen that is presented to said user; d) an active Task Model database, being in data communication with said processing unit, for storing said active model, wherein data transferring and storing is minimized to screen unique identifier and; e) an analyzer for comparing said active Task Model to said passive Task Model and for generating usage patterns for said user.
15. The system according to claim 8 , wherein each of the model entities is associated with a unique primary identifier and with a base identifier, said base identifier being derivable from a parent entity when said parent entity is reused by a given model entity and being identical to said primary identifier when said given model entity is a parent entity.