I think they can retain customers’ past flight records and maybe list of media played in flights. That said it’s almost guaranteed some ad marketing corpo is behind, and EULA is always vague enough to allow sharing external party…

Your own learning resources + Anki.

However, this requires significantly larger amount of work compared to said learning apps, which has establisged learning course in form of easily digestable chunk.

You need to digest textbook and such on your own into small chunks, then Anki cards. It’s essentially building course by yourself.

Fluent Forever from Gabriel Wymer gives some idea on how to utilize Anki, though the author moved to build his own closed source app.

I used zoom for some hobby online meetups. The majority used zoom. I’m assuming that it’s organizer’s choice, which they’re familiar at work. I’d love to spread a word for FOSS alternatives, but sadly I’m not the person organizes events.

The thing is for most people zoom is equivalent of video conference. Zoom has soared its publicity in WFH era, and Zoom decides to (like every corporation does) utilize it, milking every possible profit from it.