Design
Describe the final design of your interface. Illustrate with screenshots. Point out important design decisions and discuss the design alternatives that you considered. Particularly, discuss design decisions that were motivated by the three evaluations you did (paper prototyping, heuristic evaluation, and user testing).
Implementation
Describe the internals of your implementation, but keep the discussion on a high level. Discuss important design decisions you made in the implementation. Also discuss how implementation problems may have affected the usability of your interface.
Evaluation
Describe how you conducted your user test. Describe how you found your users and how representative they are of your target user population (but don't identify your users by name). Describe how the users were briefed and what tasks they performed; if you did a demo for them as part of your briefing, justify that decision. List the usability problems you found, and discuss how you might solve them.
Reflection
Discuss what you learned over the course of the iterative design process. If you did it again, what would you do differently? Focus in this part not on the specific design decisions of your project (which you already discussed in the Design section), but instead on the meta-level decisions about your design process: your risk assessments, your decisions about what features to prototype and which prototype techniques to use, and how you evaluated the results of your observations.