There hasn't been an update for Skitch since October last year. Is the app already installed on your iPad, or is it waiting, and the download has paused?
In any case, you could try removing Skitch from your iPad, and then reinstall it.
Tkz for..... After iOS I download almost all the apps which onboard again and willing for fresh and latest apps version. Now again delete and then last see what happens.
It should still be available for download, in you Purchaes tab if nowhere else. I only mentioned the lack of support because it is time to start thinking about alternative apps.
I haven't found an alternative I really like. Nothing has the same combination of features and ease of use. At some point I'll post a thread on the topic, but I keep hoping some developer will come out with a greate alternative before it becomes critical.