Who can help to deal with the jambs of the application?

Question

Mobile development

The question is:
I am the author of the application. Published on Google Play and App Store. The application is technically simple, like an e-book. I am the author of the content, and the programmer did it for me (hired through a weblancer) on the react native framework. At first everything worked fine, but now suddenly the application on Google Play on most devices began to open with empty pages, both of its versions (light and pro).
It is not possible to contact the programmer, it seems to make ends meet. I threw an application on the same weblancer, no one takes it.
Can anyone please tell me what to do with this? What could be the reason for this: programming jambs or publishing jambs, which for some reason suddenly got out in such a sad way? In short, what to do with it? I really need help.

Answer 1

0. Find a source repository
1. Find another programmer
2. Show him the source
3. Negotiate a price for his time

Answer 2

All you need is a new app. The programmer disappeared, and now only God knows how this miracle of engineering soap works.
I can offer my services as a novice developer (the design, of course, would not be so cool, and I can only take it before the new year, but for a penny and for experience).