It’s fantastic. I love the use of Flickr photos — great cross-pollination.
1) I wish you could “like” the Flickrs photos from the app.
2) The app icon is awful. I would never want that on my homescreen. Yahoo, some advice: kill the branding. The purple already screams “Yahoo!” — remove the name and make the cloud and sun slightly larger. Repeat on all other apps. Boom. You’re welcome.