I literally just typed in Anki on Google and the first link to their homepage very obviously explains that it's free to use even with synchronization across multiple devices. The only cost I can think of is that they charge a one time fee for the mobile app for iOS, but the clients for android and desktop apps for computers are completely free. I have no idea where you got your information from but perhaps next time do a basic cursory search on the internet instead of querying ChatGPT.

Not sure where you found a subscription to Anki, but it's free and open source: https://github.com/ankitects/anki

The iOS app is a one-time payment though.

This article is definitely not written with an unfamiliar reader in mind though, that's for sure.

Anki is free. And the concept of SRS is free. There are apps that are clearly very good at capitalizing on the success of Anki and charging. If you found the paid iPad app, that's a one time fee to help the developers maintain it in the app store. I think it's pretty steep but otherwise Anki is free on other platforms. I actually don't like Anki but don't want it to be mischaracterized

Anki is an open source app: https://github.com/ankitects/anki

Only the iOS version costs money, which is probably their only revenue stream.

Uh, I'm on Windows and Android and never once paid for it. Not at what you're seeing. iOS pricing?

Anki is free on anything but iOS. Don't know why the iOS app is the only one with a fee.