No, you don't have a virus (none have been reported to be in use against the iPad).
What you probably have is overextended RAM. So, try one of these three things (in the order typed ... and you may have to do them all):
1) Fully Close All Apps: Double tap the Home button (or do a 4-finger swipe up) to reveal a row of icons in the multi-tasking bar. Press and hold an icon until they all start to wiggle and you see a red circle with a minus sign ("-") in the top left. Press the minus sign to fully close all the apps. Don't worry, it won't remove the apps from your iPad, just from the iPad's resident memory. Then,
2) Restart: Hold down the power button until the power off slider appears. Slide it off. When the iPad finishes shutting down (it goes fully dark and you don't see a spinning wheel), hold down the power button again until the Apple logo appears.
That may take of it, so try your app again. If it still happens, then do this:
3) Reset: Hold both the power and home buttons until the screen goes dark and the Apple logo then appears (the slide to unlock screen may or may not appear). Once the logo appears, release the buttons. After a time, your homescreen will appear. Please note that it may take some time for the Apple logo to appear or for your homescreen to appear (or both). This is normal. Eventually, the homescreen will appear.
The iPad is a computer and, as such, sometimes needs a swift kick in the software. So, this should do it. If so, yay. If not, holler back and we'll try something else. Good luck and do let us know how you get on.
Marilyn