The new Flickr changes are a nice step, but very late in the game. I gave up on them two years ago and migrated to Google - Picasaweb at first but now that's been assimilated into the Google+ brand. I'll probably try uploading some new stuff to Flickr because 1 terabyte of full resolution photos is a huge carrot. But...
I went to look for their desktop apps to upload photos and they're still around, unchanged since 2009. Not one single update or bug fix in FOUR years. That's the Flickr I left.
I tried to use the new Android app and I couldn't log in. Looking through the app reviews, plenty of other people had the same problem. That's the Flickr I left.
I tried the Windows Phone app, but it also just errors out logging in. The reviews are full of people having the same issue. The app hasn't been updated in 15 months. That's the Flickr I left.
I tried the iOS app but it hasn't really changed, despite having an update published today. At least I was able to log in. It still isn't a universal app, so it doesn't really support the iPad. That's the Flickr I left.