I have a hosted solution on FMSA12. I have tested it before but it is not working now. The user can't view the container object on their iPhones. The "view button" is greyed out but if I login as admin with full access has no problem. I have not had much modification to the security, relationship design, etc. Currently I am using FMPA13 for development work.
I thought if the user is able to view the image, it has passed the security check, in this case View Only for this field but he can't continue to view where it can be zoomed, pinched, and even email.