Colorbay is a beautiful iOS app that lets you browse images from popular photo-sharing sites like Instagram, 500px, and Flickr. If you are a longtime user of these services, Colorbay is also a time capsule that lets you rediscover old favorites. For example, Instagram only shows the last 300 photos you’ve liked because the service wants to make sure it “runs smoothly as the app becomes available to a growing number of people.”

That might seem like a lot, but over the past three years, I’ve liked way more than 300 photos on Instagram, including pics of my friends’ children as they grow up and images from design-related accounts that I save for inspiration.

I have even more old favorites on Flickr because I joined in 2004 and was an avid user. Back before Facebook became widespread, Flickr was my favorite site because there tons of very active groups for things ranging from Japanese Rement miniatures to vintage clothing.

But I’ve stopped visiting Flickr as often as I used to, partly because most of the people I met on the site have migrated to other social networks. I also disliked last year’s major redesign and Flickr’s Favorites page was never easy to navigate in the first place.

end on Pinterest or Evernote to catalog most of my favorite images, but Colorbay’s “My Likes” stream is a welcome trip down memory lane. I found photos I haven’t looked at in almost five years, but still enjoy. It’s also a fun way to browse my own old snapshots.

Colorbay, which is also available for iPads, displays photos in a mosaic-style stream that automatically plays unless you pause it. It currently allows you to browse your timelines and popular photos from 500px, Flickr, Instagram, Pixter, and App.net. Colorbay’s cool “Throwback” feature automatically delivers a random mix of photos from all services, while “Lomography” delivers film (or film-like) photos with that tag. You can also search your own tags.

Even if you don’t like to wallow in nostalgia as much as I do, Colorbay is also a fantastic photo discovery tool and a great piece of eye candy.