Dynamic Android & iOS Fiat to Crypto App

I'm in need of a modern and interactive mobile application that operates on both Android and iOS platforms. The app will facilitate the conversion of fiat currency to cryptocurrency, and vice versa.

Key Functionality:
- Fiat to Crypto Conversion: The app needs to perform seamless conversions from fiat to crypto, with up-to-date rates and minimal lag.
- Transaction History Tracking: Users should be able to view their transaction history, with filters for date, type, and amount.
- User Authentication: A secure user authentication process is a must, ensuring the safety and privacy of all app users.

Design: The user interface should be modern and dynamic, keeping users engaged and making the app easy to navigate.

Ideal Skills:
- Proficiency in both Android and iOS development.
- Previous experience with blockchain technology and crypto-related apps.
- UI/UX design skills to create a modern, dynamic interface.
- Knowledge of secure user authentication protocols.

Experience in developing similar apps will be a significant advantage. I'm looking for a freelancer who can deliver a high-quality, functional app that meets these specifications.