I've been looking for something like this but as a desktop photo backup app with cloud option. With two young kids I have tons of pictures and videos to wade through and its just not cost effective to store it all on the cloud when 2TB drives cost $100. But it is _such_ a pain for my wife and I when we consolidate pics from our various devices and then do a backup to multiple USB drives. And its just going to get wor…
Even if all you do is organize by date and show the first few photos for each day ("featured" photos), that's enough to vary the stream of photos people browse through.
I speak from experience, as someone who runs a photo-sharing site that organizes by date. I also make it easy to switch between featured/non-featured for any photo, but doing such switching is not a prerequisite. You already have a nicely varied collection just by uploading.
From what I've seen of Snapjoy so far, their format also guarantees variety. I haven't seen the fancy algorithms in action yet, but I imagine there are techniques one could use to make the initial set of "featured" photos more likely to be varied.