Develop a Mobile Application with Admin Panel and Backend

I am the UI/UX Designer of the entire application. I used sketch to design our masterpiece.
We hired a development team located in India via Upwork about a year ago, and since then they have not finished the application and they took advantage of us via hourly billing. We are in search of experienced developers to help us finish our project within our budget and on time. 

Our project is a mobile application that allows students to register to create and manage experiences.

We want to work by milestones, and have created a milestone document (feature list) on google sheets that already has an hour estimate included (estimated by a firm in Russia, so should be accurate). Our project deadline is Aug 1st. 

We are building this application using React Native for both Android and iOS. Our goal is to build a Minimal Viable Product so that we can bring it to the student market at various schools and within the first half year of production, get a solid user base of manually on-boarded students with metrics and go to investors and get funding. Post funding we plan on expanding our startup, our team, our brand, and will begin building out our application with full functionality using Native technologies.