Flutter to Kotlin Code Migration

I need an existing Flutter project re-written in Kotlin. The main goal of this transition is to simplify maintenance. The new Kotlin version should retain all functionalities of the original Flutter project.

The app is identical to this https://play.google.com/store/apps/details?id=io.walletcards.android
Please make a rough estimation and timeline based on a provided link.
Exact app will be provided only to a shortlisted candidates.