1. Check Availability: Visit the App Store to determine if Shadowrocket is already installed. If not, download it from the developer's website or through the developer's app store.

2. Install the App: Once downloaded, open the app and install it on your iOS device.

3. Access Settings/Build: After installation, open the app. Navigate to the settings or build options. Typically, this involves clicking on the "Create App" button or following the app's instructions to start building.

4. Follow Installation Guide: Review the app's installation guide to understand the steps required. This might include dragging and dropping, or using drag-and-drop features for building apps.

5. Troubleshoot and Fix: If you encounter errors, use the Help section or community forums for assistance. Look up tutorials or guides to help you through any issues.

6. Test on Friends: After building the app, test it with a friend's iOS device to verify its functionality and fix any errors.

7. Seek Further Help if Needed: If issues persist, consider reaching out to the community or developers for additional support and troubleshooting tips.

By following these steps, you should be able to successfully use Shadowrocket on your iOS device and build an interesting app.