I think I downloaded an app but not sure which one but now something called TouchWiz is preventing from accessing anything on my phone. I just want to return to my original phone settings but at the moment the only thing that's still there is the lock screen. I have tried rebooting to no avail. Can anybody assist in how I can uninstall this app or how I can get back to the phone I had before? I'm scared of losing all my contacts. Thank you in anticipation.