Language Learning Apps Harvest Data

https://sh.itjust.works/post/5722866

Language Learning Apps Harvest Data - sh.itjust.works

I should have known if the apps free, you’re the product. Duolingo appears to harvest the most data compared to other language learning apps. Source: Surfshark Research [https://surfshark.com/research/chart/data-hungry-language-apps]

What is “customer support data” being harvested, and how much of this is actually optional?