Can't you automatically get the same with Firefox Sync? And indeed, it seems to me the UI has changed recently. Anyway, if you have sync enabled on both desktop and device, you can see the other sync'd devices open tabs (if enabled, what you sync is configurable). From the desktop is from the hamburger menu, "Synced Tabs" icon. From Android, you now need to go to the history pane. The first line is "Synced Devices", press this to see other tabs and open any ones as needed. So instead of explicitly selecting to send a tab to a device, just wait or force a sync (on Android: from the Settings sync page) if in a rush.