Breath of the Wild: The Phantom Realm
This is a novel-length, it focuses on events that take place forty years after the events of the original BOTW game. It follows a new generation of the Hero and the Incarnation of Hylia as they are forced into dire odds far sooner than anyone ever thought possible.
A Winter's Gift
This is a one-shot story that is a snippet in time from BOTW before the 100 year battle between Zelda and Calamity Ganon. Its a fluffy, lighthearted story that focuses on the developing relationship between Zelda and her Appointed Knight.
The Heart of the Forest
This is a one-shot story that is set in an unknown future, and follows Princess Zelda as she spends time in Faron Woods alone, but is attacked by a pack of wolves, only to be saved just in the nick of time by a mysterious knight who does not know his own name or past. At first she hesitant to believe anything he says, but when she discovers his innocence, she fights to free him from the spell that has trapped him.
This is another full blown work centered on the events that began 10,000 years before the main events of Breath of the Wild. So in other words, when the Sheikah and Hylians were at their technological peak. Its a Sci-fi-ey story, and is currently in the works as of February 2018!
What Lies in the Heart of a Hero
One of my less cleverly names stories, just your run of the mill prequel story of what happened in the 100 years before BOTW.