For my team, mockups are the primary artifact for development and the requirements process. We use balsamiq mockups for confluence.
We also write use-cases to point out the workflow and for adding information such as how the system will respond to an action, UX requirements and other references. It's not ideal, because the documents are separate.
We're looking for a tool that's entirely mockup-based, with structured contextual texts to the side for requirements, system response, etc. (note: I know I can add annotations, what I'm looking for is structured entry and structured presentation of requirements).
It should also visualize the flow and states of pages in the form of a storyboard.
Does such a tool exist and could you recommend one to me?