In reply to mypyrex:
Have you looked in the 'apps' page? That's usually provided on the 'common apps' bar, and is a simple icon of a white circle with a 3x2 array of squares in it. Sometimes, apps install, but don't get shortcuts placed on one of the 'desktop' pages.
The alternative way of finding it is to go to settings/apps/downloaded, and you should find the app. Select it and you can uninstall it.
Or open the Play Store, and swipe right on the left margin, or hit the three-stripe menu icon (top left), and select 'My Apps'. Then select the 'All' tab. This should show all apps you've ever installed, even if you've subsequently deleted them. You should be able to uninstall, or update, or re-install the app.