Screen disappears each time it is used

Downloaded this yesterday and have tried several times to use it with the same results. I can make a change to a card, or add a card and it sticks and shows up on the web site but when I leave the App for Trello screen. The screen disappears, can not be located at the bottome of the screen with the other programs. It is still running according to the activity monitor but you have to force a quit and restart the program to see it again. Even though the cost is low I’d say it is not worth it until this major bug is fixed. I’m running Yosmite on a MB Pro.

Bob_NP about App for Trello: Collaboration Tool for Organization