Creating a photo to cartoon app similar to Deep Art Effects involves several key steps, including:

1. Research and Planning: Begin by conducting thorough research on existing photo to cartoon apps, including Deep Art Effects, to understand their features, user interface, and user experience. Identify what sets them apart and determine the features you want to include in your app.
2. Define Features and Functionality: Based on your research, outline the features and functionality you want to incorporate into your app. This may include photo editing tools, cartoon effects, customization options, social sharing capabilities, and more.
3. Design User Interface: Design a user-friendly interface that allows users to easily upload photos, apply cartoon effects, adjust settings, and save or share their creations. Focus on simplicity and intuitive navigation to enhance the user experience.
4. Develop Algorithms: Develop algorithms for transforming photos into cartoons. This may involve techniques such as image segmentation, edge detection, color quantization, and stylization to achieve the desired cartoon effect. Consider leveraging machine learning and AI technologies to enhance the quality of cartoon conversions.
5. Implement Photo Editing Tools: Integrate photo editing tools such as cropping, resizing, and adjusting brightness/contrast to give users greater control over their images before applying cartoon effects.
6. Optimize Performance: Optimize the app's performance to ensure smooth and responsive user experience, even when processing large image files or applying complex cartoon effects. Consider implementing cloud-based processing for resource-intensive tasks.
7. Testing and Iteration: Conduct thorough testing of the app across different devices and platforms to identify and address any bugs or usability issues. Gather feedback from beta testers and iterate on the app based on their suggestions.
8. Launch and Marketing: Once the app is polished and ready, launch it on app stores such as the Apple App Store and Google Play Store. Develop a marketing strategy to promote the app and attract users, leveraging social media, app store optimization, and other channels.

By following these steps and investing time and resources into development and testing, you can create a photo to cartoon AI tool or app similar to Deep Art Effects that offers users a fun and engaging experience.