Convert Android App “Protube” (90%Java, 10% Kotlin) to 1) React Native or Flutter + 2) Web Version – YouTube Player. (with Custom Ad Server)

Project Description
We are seeking an experienced mobile and web developer to rebuild an existing Android application, which is a lightweight YouTube player and downloader, integrated with a custom advertising system (not using AdMob but a PHP-based server called AdAdmin). The current app is based on ProTube (90% Java / 10% Kotlin), and we want to extend it in two directions:

1. Cross-Platform Mobile App (Flutter or React Native)
You will rebuild the app using Flutter or React Native, with the following requirements:
Fully functional on both Android and iOS
Seamless integration with our custom AdAdmin server (via PHP/MySQL API)
Ads are not powered by AdMob – all banners/video ads come from our own API (get_banners.php)


[A] Ad Display Logic via JSON Policy (served from AdAdmin)
Each app instance should fetch a custom .json policy file from a remote URL to determine where and how to show ads. For example:
{
"entry_ad": true,
"scroll_ad_frequency": 5,
"exit_fullscreen_ad": true,
"download_click_ad": false
}
The mobile app will load this file at launch and dynamically apply the ad rules.
Each customer (restaurant, hotel, garage, etc.) will have their own policy file.
The app must support a fallback default configuration in case the fetch fails.

2. Web Version (Player + Ad Integration)
The same logic and UI should also be ported to a Web version, using a modern front-end stack:
Player must support YouTube video playback
Display ads according to the same logic (read from JSON Policy)
Clean, responsive UI suitable for tablets, smart TVs, or infotainment screens
Preferred technologies: React, Vue, or Flutter Web.

Skills Required
Java/Kotlin (for understanding the current app logic)
Flutter or React Native (cross-platform)
REST API integration (GET JSON from our ad server)
PHP/MySQL knowledge (to work with our existing AdAdmin system)
Optional: experience with ad serving, theme-based rendering (e.g., dark mode)



We Provide:
Full access to current Android app source code
PHP script for banner delivery (get_banners.php)
Access to our test server with AdAdmin