Mobility patterns play an important role for performance evaluations of mobile networks. To simulate user movement, existing simulation tools provide only a few simple mobility models (e.g., random movement) suitable for particular scenarios. To evaluate a new scenario, an appropriate model needs to be created, but this requires extra work that distracts the researcher from his/her main task. In general, three key elements determine the mobility of users: the spatial environment, the user trip sequences, and the user movement dynamics (e.g., speed). In this paper, we introduce a meta-model that integrates these three elements in an easy-to-use framework, allowing a flexible modeling of user mobility in custom scenarios. The framework is available for download as a stand-alone trace generator and may be used together with any simulation or emulation tool for mobile networks to evaluate a specific scenario.