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 mul

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.