Unable to delete third-party app from iPad
From this site:

Sometimes iPhone applications get stuck waiting or loading when installing. These apps might be frozen with a blank icon and no way to remove them for days. Holding down on the home screen to delete the stuck app won't even show the black circle with an "x" that appears on other icons. Here are instructions on how to delete these waiting applications:


Reboot your iPhone normally. See this link for instructions on how to restart your iPhone.
If the apps are still stuck on the home screen, try logging out of the App Store temporarily. Navigate to Settings -&gt; iTunes &amp; Store -&gt; Apple ID -&gt; Sign Out. Now open the App Store and Navigate to the Featured section. Scroll to the bottom of the page and touch the Sign In -&gt; Use Existing Apple ID. Log in and the stuck apps should reset.
Still have strange icons on the screen or frozen downloading apps? Connect your iPhone to the computer and open iTunes. Navigate to the app store. Install the apps you are having a problem with on the computer then sync your iPhone.