Supported Features
-
Dark Interface
Casto: AI Character Fiction
My First Casting Universe
Only for iPhone
Free · In‑App Purchases · Designed for iPhone. Not verified for macOS.
iPhone
My own casting universe — Casto.
Create your dream cast and put them in stories only you'd write.
Watch their filmography grow into your own world.
AI Fiction with Your Own Cast!
Casto is where your imagination becomes fiction. Create the characters who live in your head — every detail, every quirk — then cast them into AI-written novels that unfold one episode at a time.
Casto is an AI fiction app — half story generator, half interactive fiction — that lets you cast original characters into branching, multi-episode novels.
— WHAT YOU CAN DO —
• Cast your own characters.
Design original characters with names, photos, MBTI, occupations, and backstories. Reuse them across an entire universe of stories.
• Generate multi-episode novels.
Sketch a plot in a line. Casto writes a full episodic novel starring your cast — in romance, fantasy, comedy, or thriller.
• Shape the story's direction.
Every chapter ends on a branching choice. Pick the path, and the next episode unfolds from there.
• Build a universe, not just a story.
Every character you make joins your personal casting universe. Cast them into new stories, watch storylines intersect, and grow a world only you could imagine.
— HOW IT WORKS —
1. Create your characters — name, photo, MBTI, occupation, backstory.
2. Cast them as leads in a new story (romance, fantasy, comedy, or thriller).
3. Steer each chapter with a branching choice. Casto writes the next episode around your call.
4. Reuse your cast in future stories. Your universe grows.
— WHAT MAKES CASTO DIFFERENT —
Most AI writing apps forget your characters the moment a story ends. Casto doesn't. Every character lives in your personal casting universe and can return as a lead, a love interest, or a foil across as many novels as you want to write. Less prompt-tweaking, more reading the fiction only your characters could star in.
— WHO IT'S FOR —
For readers who've always wanted to write the fiction they love. For writers who never tire of casting new leads. For anyone who has ever closed a book wondering, "what if my own character had been the lead?"
Casto turns "what if" into "next episode."
Terms of Use: https://spectacled-curler-cda.notion.site/Casto-Terms-of-Service-3557d7acbcce80a29425e28336318611
Privacy Policy: https://spectacled-curler-cda.notion.site/Casto-Privacy-Policy-34d7d7acbcce80c89eb7f12478c1e1d2
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
We have further improved the app's usability and stability.
The developer, Giyeop Hwang, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Used to Track You
The following data may be used to track you across apps and websites owned by other companies:
- Location
- Identifiers
- Usage Data
Data Linked to You
The following data may be collected and linked to your identity:
- Purchases
- Location
- Contact Info
- User Content
- Identifiers
- Usage Data
The developer indicated that this app supports the following accessibility features. Learn More
Information
- Seller
- Giyeop Hwang
- Size
- 120.1 MB
- Category
- Books
- Compatibility
Requires iOS 15.1 or later.
- iPhone
Requires iOS 15.1 or later. - iPod touch
Requires iOS 15.1 or later. - Mac
Requires macOS 12.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
English and 5 more
- English, French, German, Japanese, Korean, Traditional Chinese
- Age Rating
13+
- 13+
- Infrequent
Cartoon or Fantasy Violence
Realistic Violence
Profanity or Crude Humor
Mature or Suggestive Themes
Horror/Fear Themes
Alcohol, Tobacco, Drug Use or References
Sexual Content or Nudity
Guns or Other Weapons
- In-App Purchases
Yes
- 10 Extra Slots $29.99
- 5 Extra Slots $19.99
- 1 Extra Slot $4.99
- Casto Pro Monthly $9.99
- 1000 Popcorn $4.99
- 10000 Popcorn $69.99
- 5000 Popcorn $39.99
- 2000 Popcorn $17.99
- 1000 Popcorn $9.99
- 500 Popcorn $4.99
- Copyright
- © 2026 Lab Yesterday