If you’re referring to the Kotlin gradle plugin/version, we try to keep the latest versions when writing the tutorials, and as Kotlin is released, it’s a bit hard to follow up all the updates. :]
You can always update the versions yourself when you open up the projects, there shouldn’t be any breaking changes!
If you’re referring to the actual android gradle plugin, then 1.2.50 is a bit old, and as such we haven’t gone that far back. But if you’re using newer AndroidStudio versions, you’ll of course be prompted to update them when running projects.
Thanks for the feedback and the question, hopefully this resolves your concern.
Sorry for the late reply, I though I had responded to your question, but something must have went badly. I have a personal learning project which I’ve built with FB. But it’s very outdated: GitHub - filbabic/FirebaseChatApp.