If in the project selection user interface, you can start a new project by tapping the "add image" icon in the lower right (looks like an image of a landscape with a plus sign in the corner) > Local Photos. The project will start with your imported image as a layer.
If already in a project, there's a similar icon in the upper left, 2nd from the left. This will import the image right into a new layer in your project.
Be aware that, where the "Local Photos" option is concerned, PS Touch only monitors the default system folders for images. (For example, on Android, it's "Pictures.") Be sure to place your images in there so PS Touch can find them.
That is brilliant. Thank you. Your advice worked perfectly and I've managed to access my photo files.