Trivia Contest App with Leaderboard

I'm seeking a developer for an app that hosts trivia contests. This app will cater to individual participants and feature a comprehensive leaderboard with daily, overall, and category-specific rankings.

Key Features:
- Trivia quizzes as the sole contest type
- Individual participation only
- Leaderboard displaying daily rankings, overall rankings, and category-specific rankings

Ideal candidates should have:
- Experience in app development
- Understanding of trivia-based quizzes
- Ability to create engaging, user-friendly interfaces
- Skills in implementing complex ranking systems

Please provide examples of similar projects you've completed.