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Историческую версию Floating Action Button можно получить на Android
Образец для библиотеки FloatingActionButton с открытым исходным кодом.
Sample for the open-source library FloatingActionButton.
Android floating action button which reacts on the scrolling events. Becomes visible when an attached target is scrolled up and invisible when scrolled down.
Sources: https://github.com/makovkastar/FloatingActionButton