Almost there
The fact this app works at all to serve react native apps on device is impressive to say the least. Well done there. However, there are a few quality of life issues that make it hard to work with. The code editor could use some love, the syntax highlighting is good however manipulating text is a lot harder than it should be. Copy/paste is hard to access and the carat actively tries to avoid being placed inside existing code which is a big problem for maintainability. There's a pretty steep learning curve for individuals new to react native. The built in navigation features are great but it would be better if it were an option. A sample project included with the app would do it wonders. Something the user can create from a template, run, edit, save and recreate from the template if necessary. A kind of playground of sorts that demos all this app can do.