I have a mobile app in development but it was not completed i need urrgently.

I have a simple mobile app which was started and the project abandoned for a while. i have the source code for the app but i don't have the admin panel source code. the developer is unreachable. i need some one who can continue the app or start afresh and give me something very similar with a few modifications i will mention. the app uses google map and i have a cloud account. Please be sure you can produce both ios and android using flutter before you bid.