Difficult. Building the app won't be the end of this game and anyone in the US that can build an app is likely already hired. My advice is that you try upwork.

Difficult. Building the app won't be the end of this game and anyone in the US that can build an app is likely already hired. My advice is that you try upwork.com and divide the path to build the app into steps of 50 USD each, paying for each step completed and follow yourself the progress.