Stowly
AI-powered magical bedtime stories for children
A full-stack iOS app that generates educational bedtime stories for children using both on-device Apple Intelligence and cloud-based AI, featuring a complete subscription system with virtual currency monetization.
Tech Stack
The Challenge
Parents struggle to find engaging, educational bedtime stories that keep children entertained while teaching them something meaningful. Existing story apps either require expensive subscriptions with no free tier, lack educational value, or don't support multiple languages for bilingual families. The technical challenge was building an app that works seamlessly both online and offline, supports on-device AI for privacy-conscious users while offering more powerful cloud AI for premium features, and implements a fair monetization model.
The Solution
Stowly implements a unique dual AI provider architecture that gives users choice between privacy and capability. Free users can generate unlimited stories using Apple Intelligence (on-device) with no sign-in required, while premium subscribers gain access to Cloud AI for richer stories, AI-generated illustrations, and professional narration. The backend runs on Supabase with 13 Edge Functions handling secure JWT authentication, atomic diamond transactions, and automatic refunds on generation failures. RevenueCat manages subscriptions with real-time webhook synchronization.
Results
Key Features
Dual AI Provider System
Per-story choice between free on-device AI (Apple Intelligence) and premium cloud AI. No vendor lock-in, seamless switching.
Educational Story Generation
AI stories include vocabulary words, educational topics, and moral lessons. Age-appropriate for children 3-12.
Word-by-Word TTS Highlighting
Advanced text-to-speech with synchronized word highlighting during playback, enhancing reading comprehension.
AI Image Generation
Poster illustrations via Apple Image Playground (on-device) or Cloud AI with child-safe prompt enhancement.
Diamond Virtual Currency
Transparent usage-based pricing with full transaction history, automatic refunds on failures, and welcome bonus.
Multi-Language Support
Six languages with culturally-adapted storytelling styles and language-specific prompts for authentic narratives.
“My daughter asks to 'read stories' every evening now. It doesn't feel like learning to her.”
- Beta Tester Parent, App Store Review