Load
Load functionality is not found in the "File" menu, but as a button in the bottom-left corner of the Editor view. Press it to get to the Source browser view to select an image source. JPEG is currently the only file format supported.
Save
Press on this menu entry to save the image to a JPEG file. It never overwrites any existing files, there will always be a new file. If you loaded a file from phone or memory card, the new file will be saved in the same folder with the same name plus an added number. If you took a picture with the camera, the saved image will exist in the same folder as the original, taken picture.
Discard
Frees all (memory) resources taken by the loaded image, all changes made get lost. There is not as much memory available on a mobile device as on a personal computer - this is why you sometimes need to free memory with this button to let the file browser be able to display all images of folders that hold a lot images (if big preview mode is active - no need to free memory in system preview mode). PhotoRhino tells you, if there is not enough memory for some of its operations.