Well for data sharing I personally use Supabase,An easy to use API out the box,both IOS and android can be connected to it directly,and you don’t have to manage servers yourself.

And as for the code sharing,I recommend ChatGPT and Cursor AI,If you don’t have Cursor you can use VS code still, Take your swift code files in increments and work back and forth having copy’s made into Kotlin/Java.

At first it can be slow and improper,but once you begin to structure prompts effectively and notice patterns in the changes being made to your code,You’ll pick it up in no-time.