I am not really following what the need for special software is to see these photos if accessed from your "personal cloud" hard drive. If you give Uncle Joe the password to access the personal cloud drive folder the way that you would remotely and Uncle Joe gets to your drive he will see folders just like on any computer. He opens the folder and sees the files - clicks on one and it opens on his PC with whatever default jpg software he has on the PC, tablet, or smartphone and he sees it. If your cloud drive is set up with the ability to access only folders you specify and you can make the files in those folders read only so that they cannot be deleted or overwritten, it should all just work. Special software should not be necessary. The other way to do this so that photos cannot be altered is to put your photos into a slideshow - many free programs to do this and when the slideshow file is clicked it self-plays. Then if someone wants a copy of a photo they can ask you for it and you email it to them.
