iOS AR gallery viewer

This is a simple app. The app should be able to display 3d objects. Option A) The 3d gallery would be dynamic (coming from a folder named "main\usdz, and main\thumbs"). The thumbnail images will always have the same size. The app should have display the 3d objects in two or three columns depending on the orientation of the device. The target device is an iPad. The name of the thumb would start with two digits to indicate the order of appearance in the gallery (01_xyz.png, would be first, etc., etc ) and would correspond to a file named 01_xyz.usdz. Option B). I specify six objects and their thumbnails that would be hard-coded in the app (which would make the app limited to only displaying this 6 objects). The gallery would have a logo at the top. When the user taps on a thumb, the object is displayed, and if the user exits the AR he is sent back to the gallery.