My first thought once I saw this was "flutter". It's really getting a lot of market share in mobile dev and all you need to write is Dart, for better or worse. Also, whenever you need to do iOS specific duct-tape-plumbing, it seems that Obj-C is still more capable than Swift because of the accumulated legacy.
However, take it as an educated guess rather than a fact since I have never been a mobile dev apart from hobby apps.
EDIT: typos.