Can't download applications from App Store on my iPad 2 iOS 9.0.2

After updating my iPad 2 to iOS 9.0.2, I am not able to download any application from the App Store. When ever I hit the install button, a white icon comes on my homescreen and its on waiting then after a few minutes a pop up shows up saying "Unable to download app, the app can't be purchased at this time" it's very anoying so I need help!!