Allow me to throw my hat in the ring with a mockup of this feature that I too would very much like to see implemented.

Consider using different colored stars¹ for various user-defined categories ("tags").

##Favoriting:

![favoriting mockup][1]

##Viewing Favorites: ![viewing favorites mockup][2]

The biggest issue I see with this is the major overhaul it would require. To get around that, I would suggest a "default" category where all favorites land in implementations not yet supported (mobile, apps, API, etc.)

¹ Rainbow stars make me think of unicorns, so this can't be a bad idea, can it? [1]: https://i.sstatic.net/LYrdD.png [2]: https://i.sstatic.net/7mtS7.png

Allow me to throw my hat in the ring with a mockup of this feature that I too would very much like to see implemented.

Consider using different colored stars¹ for various user-defined categories ("tags").

Favoriting:

Viewing Favorites:

The biggest issue I see with this is the major overhaul it would require. To get around that, I would suggest a "default" category where all favorites land in implementations not yet supported (mobile, apps, API, etc.)

¹ Rainbow stars make me think of unicorns, so this can't be a bad idea, can it?