I do not own any mobile devices, haven't found a need for one yet.
I just had a friend check ATP on a mobile set up for me. We went into the multi-plant photo database by the blue "Goodies" bar as you must have. The page you are taken to shows you the new multi-plant photos, (the "frequently tagged plants" box is on the top with the "Daylilies" link inside).
Adding these images to the multi-plant photos is what I would consider the best option based on the current set up of ATP. The multi-plant photo database is set up to receive these types of images, the labeling system is there, easy to use, automatically puts the image in the individual plant page ... I suggest you re-post your questions about creating a separate database or a search function for these few images over in the Plant Database forum. The Plant Database forum is best suited for these types of questions.