I have on the order of 120,000 photos in my collection. This app is amazingly fun for finding new ways to look through them and relive memories. When I first downloaded it, it crashed during setup. Creator response was immediate and impressive. Within a week he had two testflight betas out and fully resolved my issues.
One feature I'd love to see is an eye dropper to select a specific color in an image as a more granular way of drilling in. It would also be nice if he pulled the metadata from the picture of where it was taken, or offered a link to the image in photos. These are minor future things to think about, though.
If you have a large collection and want some fun, give this app a try.