How do replay slots work and how can I purchase/use them?

How they work: 

• Replay slots let you to start your story from the beginning, and have different levels of progress saved in the same story. 
• For example - if you've been reading your story but want to start your story from the beginning, you can use a replay slot to start over (while still having your progress saved in the other "slot.")

How to buy replay slots:

1. Wait until the end of a chapter. You'll see a button that says "Replay Options."
2. Tap the "Replay" options button and you'll see 3 options to replay your story from the beginning. The first slot is free, and you can purchase another slot.