Mashups integrate a set of Web-services and data sources, often referred to as mashlets. We study in this paper a common scenario where these mashlets are components of larger Web-Applications. In this case, integration of mashlets yields a set of inter-connected applications, referred to as Mashed-up Applications (abbr. MashAPP). While interactions between the mashlets enrich the individual applications, they also render navigation within them more intricate for the user, as actions in one application may affect others. To assist users in their navigation through MashAPPs we provide a solution based on a simple, generic model for MashAPPs and navigation ows within them. Queries over the model allow users to describe navigation ows of interest, and an effiective query evaluation algorithm provides users with recommendations on how to navigate within the MashAPP. The model and algorithms serve as a basis for the COMPASS system, built on top of the Mashup Server.