Does anyone know what is the status of Google One-tap AKA YOLO project?
It seems like all the official documentation on One-tap is gone. The cached version states:
The beta test program for this API is currently closed. We are improving the API's cross-browser functionality and will provide updates here in the coming months.
There are quite some websites which are still using this technology, either because they were in Beta and/or whitelisted by Google.