App opens every time I unlock my phone

if you have not found a solution/answer, here is one.

Its nothing to do with the iphone or the app, its just that you are accidentally touching the app when unlocking the phone. I had this problem and did some research/testing. It happens because of the extra touch from unlocking the phone is propagating to the home screen. If you change the passcode with the different last digit from your previous passcode's last digit, the app under that digit on the home screen will open, its because you are touching it one time more than required. Ex. I had passcode 9999, it is natural for me to hit 99999 or 999999 quickly to unlock the phone. So the app under 9 on the home screen after unlocking the phone will open. I tried changing the password to 7777 and the app under 7 was opening. Its just usage error.