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Enabling Google Dialer’s Floating Bubble
You’ll need to download Google Dialer if you don’t have it already. You can download the latest on https://forum.xda-developers.com/android/apps-games/apkmirror-web-app-t3450564. To enable it as the default calling app, go to “Settings” then “Apps” and press the settings cog at the top and tap “Phone”. Change the default phone application to the Google Dialer. It’s called “Phone” too, but the one not marked as default or system will be the one you just installed if you haven’t got any other dialer apps on your phone.