Based on your query, I would recommend SchoolAI as it has a feature that allows for the generation of various types of documents, including student progress reports. This feature is powered by AI, which aligns with your request for an AI report writing app.

The AI-powered document generation feature of SchoolAI can save you significant time and effort in writing student progress reports. It can generate these reports quickly, allowing you to focus more on teaching and less on administrative tasks.

Moreover, SchoolAI offers a range of other features that could be beneficial in your teaching process. For instance, the AI-powered tutors can provide personalized guidance for each student, and the automated administrative tasks can free up more of your time for student interventions and instruction adjustments.

The interactive learning activities and assessment creation and monitoring features can also help you track student progress more effectively, which could further enhance the quality of your progress reports.

In terms of pricing, SchoolAI is free for teachers, with a Pro plan available for more extensive features. This makes it a cost-effective solution for your needs.

In conclusion, SchoolAI can effectively address your need for an AI report writing app for student progress reports, while also offering a range of other features to enhance your teaching process.