1. A method for generating an interactions explorer for a user interface prototype comprising: defining and displaying on a display, for a user interface (UI) in a user interface prototype, a screen flow comprising one or more screens, the flow representing branches in the UI prototype; detecting one or more prototyping actions while a user creates the user interface prototype, wherein the one or more prototyping actions are related to screen flow in the user interface prototype; adding the one or more prototyping actions to an interaction hierarchy that outlines the screen flow of the prototype; automatically generating and displaying, in a portion of the display, in response to adding the one or more prototyping actions to the interaction hierarchy, an interactive visual depiction of the interaction hierarchy; generating, in the interactive visual depiction, a flow for each path through the user interface prototype, the flow comprising one or more screens coupled via one or more interactions; detecting selection of a screen from the one or more screens; allowing a user to edit the selected screen of the user interface prototype; generating a new interactive visual depiction based on the editing; and propagating changes made in editing the selected screen to screens which flow from the selected screen via one or more interactions.