I have had no problems at all on my iPad Air 2 and my iPhone 5S. What troubleshooting steps have you taken in order to try to resolve your problems? Anything at all? I'm guessing, no, or you would have listed the things that you tried and didn't work for you.
SStart with very basic steps. Close all apps first.
Press the Home button two times quickly. You'll see previews of all recent apps, Swipe to get to every app that you want to close. Swipe up on the app's preview to close it.
Next Force restart the device. To force restart your device, press and hold both the Sleep/Wake and Home button for at least 10 seconds, until you see the Apple logo.
If that didn't help, Reset all settings. You will not lose any data, but most of the device settings will have to be entered in the settings app again. Settings>General>Reset>Reset all Settings.
If all of that fails, restore the iOS software. Backup your iPad before you restore, then restore the backup when you are done. If that still doesn't help, restore your iPad as new and start all over again. Most purchased content can be downloaded again at no charge as long as you use the same Apple ID and as long as the content is still available in the store.
Restore iPad to Factory Settings
http://support.apple.com/kb/ht1414
Download Past Purchases
http://support.apple.com/kb/ht2519