I am unable to get HP ePrint app to load onto my iPad 2 ? Basically I click to add the app in iTunes, the app appears to load on iPad but then at end of installation it simply disappears from iPad screen ? This did work going back a few weeks ago and still works using my iPod or iPhone ? I also noticed if I log into iTunes store and look at HP ePrint Home app it shows 'instal....' ? Any help appreciated ?