If you use react-native-image-picker, maybe you already have problems using android, when you click to choose where you wanna select image, the app closes with this error on logcat:

NavigationActivity must implement OnImagePickerPermissionsCallback

The quick solution to fix this, was proposed by aarontrank in this link. So, all you have to do is open ImagePickerModule in android files of react-native-image-picker, and replace  this code: (close to line 599)

if (activity instanceof ReactActivity)
{
      ((ReactActivity) activity).requestPermissions(PERMISSIONS, requestCode, listener);
}
else if (activity instanceof OnImagePickerPermissionsCallback)
{
     ((OnImagePickerPermissionsCallback) activity).setPermissionListener(listener);
     ActivityCompat.requestPermissions(activity, PERMISSIONS, requestCode);
}

to this code:

String[] PERMISSIONS = {Manifest.permission.WRITE_EXTERNAL_STORAGE, Manifest.permission.CAMERA};
if (activity instanceof ReactActivity)
{
  ((ReactActivity) activity).requestPermissions(PERMISSIONS, requestCode, listener);
}
else if (activity instanceof PermissionAwareActivity)
{
  ((PermissionAwareActivity) activity).requestPermissions(PERMISSIONS, requestCode, listener);
}

Of course you need to import PermissionAwareActivity:

import com.facebook.react.modules.core.PermissionAwareActivity;