Yes, API was the other best thing about Flickr. A friend made his fortune, especially during the exodus days of Flickr. He traveled around the world photographing some of the best pictures I have seen in my life. He retired pretty early in the Himalayas (he is originally from there).

He made Bulkr, which was one of those tools that just works and super easy to use, in getting all of your photos offline from Flickr. I don't think it works anymore. His revenue and hits went crazy after Veronica Belmont talked about it.

https://brajeshwar.com/2011/bulkr-access-and-backup-your-fli...