The easiest thing to do from the accounting and complexity perspective is to use a reseller. We use paddle.com and are very happy with them. In such setup, rese

The easiest thing to do from the accounting and complexity perspective is to use a reseller. We use paddle.com and are very happy with them. In such setup, reseller is selling your product/service and handles all the invoicing, per country tax calculation, etc. No matter how much you sell, you always get only a single invoice per month from the reseller, with only one entry - the cumulative sales from the month, which is very easy to account. If I understand correctly, Apple store also operates as a reseller (but Google Play doesn't). The drawback is that customers see your reseller company name in invoices, which can be problematic for some, but we haven't yet hear complains.