Cross-Platform App Functional Update

I have an existing cross-platform app that needs functional changes only—no design tweaks or simple bug hunts this time. The codebase is already live on both iOS and Android, and I want to keep the look and feel intact while improving how certain features actually work.

Here’s the scope in a nutshell:
• Review the current cross-platform code (React Native, Flutter, or similar—details once we connect).
• Implement the specific functional adjustments I’ll outline after you sign the NDA.
• Build, test, and verify the updates on both iOS and Android environments.
• Hand back clean, well-commented source plus updated release builds ready for store submission.

This is a focused job, so I’m looking for someone who can jump in quickly, identify the right touch-points in the code, and deliver a reliable fix without overhauling the entire project.