Applications keep crashing

does that include preinstalled apps like Safari, Mail, etc ?

If you're only experiencing it with purchased apps, use this article: http://support.apple.com/kb/ts1702

If you're also having the issue with preinstalled apps like the ones mentioned above:

1. Try doing a hard reset:

Press and hold both the Home button and the Sleep/wake button simultaneously for about 15 seconds and release when the Apple logo appears.

2. If that doesn't solve the issue, backup the device and restore it as new.

In that case, use: http://support.apple.com/kb/HT4137

NB: set up as a NEW device because a software issue will be in the backup. If the issue persists after restoring as new, you should offer the device for service.

If you get specific error messages/codes in iTunes when updating/restoring, check this: http://support.apple.com/kb/ts3694 for causes and solutions

Good luck 🙂

Stijn

Try this:

1. Close all inactive apps in the Task Bar. Double-click the Home button and hold apps down for a second or two. Tap the minus sign to close app.

2. Hold the Sleep and Home button down until you see the Apple Logo.