Story-Based Language Learning App

I want to create a simple, cute, friendly and easy-to-use language learning app. The main idea is to help people learn a language through very short and simple stories. IMPORTANT: I do NOT want any AI features in this app. No AI conversation, no AI-generated content and no AI tools. The app should be simple, lightweight and easy to use. MAIN STRUCTURE: The app should have 6 language levels: Level 1 – Very Beginner Level 2 – Beginner Level 3 – Elementary Level 4 – Intermediate Level 5 – Upper Intermediate Level 6 – Advanced STORIES: Each level should contain 6 very short stories. Total: 6 levels × 6 stories = 36 stories. The stories should be short, cute, interesting and easy to understand. The style should feel friendly and similar to simple children's stories, but the app should be suitable for adults as well. Each story should include: - Story title - Short story text - Audio narration - Play / Pause / Replay - Translation - New vocabulary - Useful sentences The user should be able to listen to the story while reading it. VOCABULARY FLASHCARDS: Each level should have a flashcard section. Flashcards should contain: - New word - Translation - Pronunciation - Example sentence - Audio pronunciation There should also be flashcards for useful new sentences. The user should be able to mark a flashcard as: "I know it" or "Review again" QUIZ: After each story, include a very simple quiz with 3–5 questions. For example: - Multiple choice - Vocabulary questions - Simple comprehension questions - Fill in the blank PROGRESS: The app should remember the user's progress. It should show: - Completed stories - Completed levels - Flashcards learned - Quiz results - Overall progress DESIGN: I want the application to be: - Cute - Friendly - Simple - Clean - Modern - Easy to navigate - Not complicated - Suitable for adults and young learners - Comfortable to use on a phone and tablet I prefer a soft, pleasant and educational design with simple illustrations/icons. IMPORTANT FOR DEVELOPMENT: I want a simple MVP with the lowest reasonable development cost. I do not want unnecessary complicated features. I do not want AI. I want the app to be built in a way that allows me to add or edit stories, vocabulary, translations and audio later without having to rebuild the entire application. Please recommend an affordable cross-platform solution if possible. Please provide: 1. Total development cost. 2. Estimated development time. 3. Recommended technology. 4. Whether the app can work on both Android and iOS. 5. How I can add new stories and vocabulary later. 6. Examples of similar apps you have developed.