Hi, JackHowse. I hated when that happened. Just go to Facebook. Select "Account." Select "Account Settings." Then select "Applications" from the menu on the left. Find PlotBot on list of apps on the right, then select the "X". You will be asked if you want to Remove PlotBot. Select "Remove."

Now, you should be able to log into/sign out of PlotBot without logging out of Facebook.