It seems that you are having some issues with the SlingPlayer for iPad application since you cannot open it once you downloaded it.
As the first step, we recommend you to uninstall it one more time. Then download this application on your computer through your App Store account. Finally, connect your iPad to your computer and install the application from your computer into your iPad 2. Make sure to follow these indications and let us know how it works for you.
Hope this helps!