Keeps shutting down. Don’t purchase if running OS 10.11.3.

Lately it will not stay running. It will only run a short time before quitting.
Still not working. 3-17-2016
Now will not run at all. Worse yet, the develper ignores my emails requesting assistance.
Also, I paid to upgrade to Pro, but the app still says “Free."

Major Henderson about Calculator Pro • Topbar App