You could always turn the App Store off in the restriction preferences...
Also, I was thinking about this very same thing today. I don't wanna upgrade Jaadu VNC because their icon is now worse than ever. How cool would it be if you could swipe the update in the App Store and an "Ignore Update" button appeared and when you tapped it, it could gray out the update. To get the update back, just swipe again and choose "Un-ignore". It could be cool.