Based on the user reviews on the App Store, here are three cons and three pros of the "Fill & Build 3D" app: **Cons:** 1. Limited tutorial and unclear instructions for new users, causing frustration. 2. App crashes occasionally, resulting in lost work and wasted time. 3. Lacks collaboration features, making it difficult to work with others. **Pros:** 1. Intuitive interface and user-friendly design make it easy to create 3D models. 2. Offers a wide range of tools and customization options for detailed designs. 3. Encourages creativity and provides opportunities for users to build complex structures.