If you work with 3D models, chances are you've encountered OBJ files. These files are widely used for storing 3D geometry data and are commonly used in 3D printing, game development, and computer-aided design (CAD). If you want to view OBJ files on your iPad, there are several apps that can help you do so. Here's a step-by-step guide to help you get started.

1. Download a 3D Model Viewer App: The first step is to download a 3D model viewer app from the App Store. There are several options available, such as 3D Viewer, MeshLab, and OBJ Viewer. Choose the app that best suits your needs and download it to your iPad.

2. Import the OBJ File: Once you have the 3D model viewer app installed, open the app and look for the option to import files. This may be labeled as 'Open', 'Import', or 'Add File'. Tap on this option and select the OBJ file you want to view from your iPad's storage or cloud storage service.

3. Navigate and Interact with the 3D Model: After importing the OBJ file, the 3D model viewer app will display the 3D object on your iPad's screen. You can use touch gestures to rotate, zoom, and pan around the 3D model to view it from different angles. Some apps may also offer additional features such as measurement tools and layer visibility options.

4. Export and Share: Once you have viewed the OBJ file and are satisfied with the result, you may also have the option to export the 3D model or share it with others. Depending on the app you are using, you might be able to save the file in a different format, send it via email, or upload it to a cloud storage service.

By following these simple steps, you can easily view OBJ files on your iPad and explore 3D models on-the-go. Whether you're a 3D artist, designer, or hobbyist, having the ability to view and interact with OBJ files on your iPad can be a valuable tool for your creative projects.