Oh that's odd... are you accessing the web app through a regular browser like chrome, safari, mozilla, etc. ? I know the Google SSO does not work if you access the web app through something like Facebook's built in browser.
I've been living in Montreal now for the last couple of years and have struggled to find people to practice speaking French with, so I created a web app to talk with an AI to improve my conversational skills [1]. I launched a few months ago and am seeing a little bit under $500/month in revenue so far.
I initially started by offering the service for free, but it eventually became too expensive to handle by myself. I then decided to switch to a paid and free tier and by that point I had amassed enough of a user base that a decent handful signed up to the paid tier. I optimized for user growth > revenue in the beginning because I kept thinking, "if people are not going to use this for free then they surely are not going to pay for it".
Anyhow, it's called Proseable and it also supports English, Italian, German, and Spanish!
Absolutely, what I've noticed is that the current apps are great for beginners but after a certain point the only way to improve your ability to speak a new language is to well... speak it. I built Proseable to help people move beyond the generic how to order a coffee or ask to go to the bathroom, and have more meaningful conversations in the real world. Check it out!