Guys I spent hours to find a good ember alternative. I've tried Dropmark: (There's no mac application) Web App is not useful. Pocket: You can't categorize Pixa: Too old Pixave: There's no iPhone App Dragdis, curator, moodboard, inboard, Pinterest, stumbledupon(mix) and many more...

Finally, I've found "raindrop.io" today. I think headquarters in Russia and I presume there's not a big team behind it. So, there's a risk to put all your ideas over there and all of a sudden the guy may decide not to continue working on it. But other than that it's the closest service to Ember so far. It has Web Application, Mac App and iPhone App(You can't upload photos from iPhone which I hate) but I'd give this a shot. If more people start using it, there's a chance that they'll improve more.

Hope you'll find it helpful ;)