San Francisco fare collection to be modernised
https://www.metro-report.com/news/news-by-region/americas/single-view/view/san-francisco-fare-collection-to-be-modernised.html
While contactless IC cards like Clipper are becoming common and are expanding in Japan, that system seems to be treated as an old style in California. The newest trend is an app that can issue tickets electronically.
I guess there will be an app where we can issue tickets of almost all the railway companies around the world in the near future.
