Flutter UI Designer - for our chat app

Hello there, hope you all are doing fine during this pandemic. We have a basic chat application with audio and video calling functionality, that is nearing completion. It is built on Dart and Flutter. We are looking for a UI/UX developer who can work on its front end development. There are a total of 30 screens. They include Splash screen, on boarding screens, OTP verification, profile set up, setting up a barcode for user (we already have the generator), Home screen, logs screen, chat, audio and video call screens, barcode scan camera UI, settings and an in app purchase page. All the functionalities are already made. You are not required to do any of the feature implementations, but the just the UI. Like changing the template lay out of UI elements, changing colour scheme, adding subtle animations, unique transitions etc. We already have access to some pre-made UI kits, which are pre animated and has the kind of UI style we are looking for. These needs to be modified to meet our custom UI requirements. The budget is $150. More details will be shared with candidates, before hiring.