Discord for me. I never heard of it before, but now that I handle students, I find it is the best product for Community Management, it can do calls, chats, focus time, announcements and engagement :)
Lingvist, which is the best app for learning new words in foreign languages. Helped me to acquire hundreds of German words, so my tutor asked me why I know so many advanced-level words while being intermediate at speaking 😅 In my opinion, the secret of success is both in a proper learning technology and strong UX/UI.
JinbuPal