Booking Mobile Application for a Restaurant/Bar (Flutter)

We have created a booking system for a restaurant (web portal) using php laravel and mysql database, the APIs are being developed following the REST response structure. We are looking to build a mobile application to allow for these bookings as well. The mobile application should be cross-platform, we are looking specifically for a flutter developer but we are open to other options if we discuss them. The developer is required to maintain the app at all times, and be available for any client requests or updates, especially maintain the versions of the code and make sure it is always updated.