This paper presents ReflectionApp, an AI-driven conversational tool designed to scaffold student reflection on project-based challenges. By combining structured prompts with LLM-generated follow-up questions, the tool aims to encourage deeper critical thinking and to support the development of reflective skills. Preliminary findings suggest that ReflectionApp enhances the depth and quality of student reflections, though challenges remain in adapting to diverse project contexts. Usability feedback indicates that the tool is effective but highlights areas for improvement, such as reducing redundancy and offering clearer guidance.