I just read your posting. It seems to be a best match for both of us.
I have a background in developing applications using React native, Xamarin forms, ASP.NET MVC, ASP.NET Core, EntityFramework, WebAPI, etc and have been doing this for 7 years.
Have developed service nation app using Xamarin forms.
Freelancer has not started the development. I had to fix one stored procedure, test and give the latest version to start the development. Source code and database scripts were provided. Agreed on the price and decided to work on future mile stones. Unfortunately he blocked the chat, can be because he got some new project or the complexity of the source code is beyond his technical skill. It should have been properly communicated, instead he blocked me which is not a professional approach.