What is Reddit's opinion of ShoeBox?

From 3.5 billion Reddit comments

You can try Google Photos, that works. If you don't like that, you can always use Flickr, they give you 1TB of space for your photos (no videos, sorry!)

If that still doesn't help you, then you can also try http://shoeboxapp.com/ they have unlimited photo backup (but watchout, they compress your photos)

Google+ photo backup can upload photos at a certain resolution (2048 px) so that they don't count towards your google data quota. This is the option I personally use. Scanned photos at this resolution should be more than sufficient for sharing with the family.

I have seen shoebox also been recommended here but I've never used it myself.

And since this is datahoarder, you could roll your own server and share your photos using something like OwnCloud or even Plex.