Amazon Rapids, the tech company’s new attempt at getting children interested in reading through a chat-based mobile app, is arriving today on Amazon Fire tablets. The app was first introduced last month as a subscription-based service that lets kids read stories across a variety of categories that are told in the style of chat sessions.

That is, both the text and the illustrations are sent in a text messaging format, while the kids control the pace of the reading, by clicking on the next chat bubble in the story’s sequence. The app also helps young readers sound out difficult words, and adds those to a dictionary for later practice. There’s also a “read to me” mode where the app will narrate the stories to the child instead.

The stories themselves span genres like adventure, fantasy, humor, mystery, science fiction and sports, and are told by the characters, like aliens invading the earth or chickens crossing the street.

Amazon says this app will now be delivered to Fire HD 10, Fire HD 8, and Fire tablets as part of the new Fire OS update arriving today. The app includes hundreds of original stories, and adds dozens of new ones monthly as part of the subscription that costs $2.99 per month. (A two-week trial is also available, to see if the kids actually like the app first.)

The other notable feature arriving in the update today is Alexa video support. Amazon’s virtual assistant Alexa was rolled out to Fire devices earlier this year, where it was able to perform tasks like playing favorite songs, opening games or reading audiobooks. Now the assistant can search for and play movies and TV shows from Amazon Video, including Amazon Channels’ video subscriptions, too.