If a company or person earns money worldwide from his home country, let's say India for clarity, does the person file taxes for all countries he has supplied goods or services to? This in the case of the Apple/Google app stores.
If someone sells in-app-purchases, through Google Play Store or Apple Store, while in India and lets say the payers are in various countries (USA, Australia, France), what happens?
It is extremely simple:
Each person (in USA, Australia, France) pays approximately say about five dollars. (It will vary slightly in each case.)
For each of those customers of the Apple/Google Store they will pay sales tax on the purchase. So for Madame in France, she may pay actually Euros4.13, in fact 0.47 goes to the French government.
Apple/Goog entirely takes care of sending the sales tax to the various governments.
Of the money "left over" after sales tax. Apple/Goog takes 30% of everything.
During the month, your product sales will be X in USD, Y in Euros, Z in AUD and so on.
Apple/Goog will convert ALL of that to INR (recall they already took their 30% AND gave the various governments their cut).
This will amount to a final INR amount for the month, let's say INR 72,100
Finally. Appel/Goog will send YOU a wire transfer for exactly INR 72,100. (BTW you get it at the end of the next month. Your bank will deduct some fees.)
AND they will make a report to the Indian tax service, that you received 72,100.
You ONLY pay income tax IN INDIA to the INDIAN authorities. The fact that Apple sold product to people in France, Australia etc is totally irrelevant. Nobody even knows this. (You won't even "know" this unless for some reason you dig in to the details. You will get an email from Apple saying "We have wired you INR72,100" and that's all you will know.)
You will have absolutely NO CONNECTION to France, Australia, USA etc. and utterly no connection to their tax authorities.
Your ONLY ITR is in India. You will have utterly no connection to any other countries, no other paperwork, no other id numbers, nothing: no connection whatsoever to any other country than India.
Say you are a large business in India that sells (say) tshirts and some of your customers are in the USA, France etc. In that case you will have to process sales tax in those countries. But your ONLY involvement with income tax is with the Indian authorities. As I explain above in the app store case, you have NO, ZERO involvement with sales tax.