Add stories to your Collections to both keep your Library organized and to let others know what you like to read. There are two options for adding content to a collection: 

From the Story Description page

1. Tap Collections button  
2. Select a Collection from pop-up screen to add the story to

From Collections Page

1. Open a Collection
2. Tap Manage button from top right corner
3. Tap Add Contents from top right corner
4. Select contents listed
5. Tap Add contents at the bottom of the screen