In my iPad settings there is an app called null what is it?
Solution 1:
It's not obvious where this app came from. According to the answer to this question, it probably is an app that was incompletely synced with iTunes.
There's nothing to worry about, and you don't need to do anything about it.
Solution 2:
You can go to Settings-->General-->Storage&iCloud Usage-->Manage Storage. Then scroll down the apps to find null and delete it.