Its a great calculator in and of itself - but quite annoyingly...I paid $8 for the pro version but it does not remove the pop up constant Google app ads every 5 or 6 calculator actions/entries.
$8 is awfully steep for "upgrading" to an app with ads. If ads dont bother u its a super calc, but def do -not- buy the pro version thinking its ad free. I made that mistake.
Wallybird324563 about The Best Calculator - Calc Pro, v6.4.0