I guess it is an error caused by not matching name of project and your registered component.
You have inited project with one name, i.e.
react-native init AwesomeApp
But in your index.ios.js file you register other component
AppRegistry.registerComponent('Bananas', () => Bananas);
When it must be
AppRegistry.registerComponent('AwesomeApp', () => Bananas);
Try to fix it.