Who was Broken Glass intended for? I can't imagine anyone declining such a flawless song like that(unless they weren't able to hit the notes in those final choruses)
Bird Set Free - Adele
Alive - Adele
One Million Bullets - Sia
Move Your Body - Shakira
Unstoppable - speculated Demi/Brit
Cheap Thrills - Rihanna
Reaper - Rihanna
House on Fire -
Footprints - Beyonce
Sweet Design - Beyonce
Broken Glass -
Space Between -
If we don't know who Space Between is for, I would seriously bet on Gwen.
Kenan Williams wrote MYB, HOF and SD with Sia, and since we know MYB was for Shakira, I think those other 2 could be written for Shakira, or they were at least pitched to her. I could hear her vocals on both of those as well.
Kanye West wrote Broken Glass with Sia so I'm assuming since he wrote Reaper which was intended for Rihanna that BG was written for Rih as well.
I just remembered Standing on the Sun is another Sia/Kurstin track too 
cannot wait for it to get here in a few hours, mailman better hurry
