A language learning app developing

A few quick questions:
• Do you need Android only or both Android & iOS?
• Will words be organized into lessons/categories?
• Do you want spaced repetition features similar to Anki?

Will students be learning from a shared vocabulary database, or do you envision personalised word lists and learning progress for each individual user?

You need development help for your Russian-speaking students to learn English fluently, where each student can create and manage their personal accounts. The reference app is like Anki, featuring daily and weekly challenges to make learning easier and smoother. Should we add both AI voice agents and text agents? Also, which preferred AI agent or LLM provider (like OpenAI, Anthropic, or a specific voice API) would you like to use in your app?

1. Is your goal primarily vocabulary memorization, or do you eventually want to teach pronunciation, listening comprehension, and sentence usage as well?

2. Should students all follow the same learning path, or will different students receive different word sets and difficulty levels over time?

3. Do you want the system to track learning performance and automatically identify which words a student struggles with most?

4. Will teachers/admins need a dashboard to create word collections, upload audio, and monitor student progress?

5. Is the long-term vision to remain an English-learning app for Russian speakers, or do you eventually plan to support additional languages and learning programs?

6. How important is spaced repetition to the learning experience? Research shows it has a significant impact on long-term vocabulary retention and would influence the architecture from the beginning.

7. If the app is successful after 12 months, what metric matters most: number of active students, word retention rates, lesson completion rates, subscription revenue, or daily engagement?