One of my friends bought Halo Wars digital version on the 360 and now cant find a way to download it on the ONE without paying for it. Any suggestions?
If the game is noted in their purchase history then it should show up automatically under their ready-to-install games on their Xbox One. If it doesn’t and the store still asks them to buy it, might need to poke Xbox Live support and see if they can help out 
Thank you!