Developing app for writing exam with qrcode scanner and web service

Using side menu app. I am having few doubts. If someone helps it will be much grateful.

1. template loads with all controls and hides. Used ng-cloak. but still problem persists.
2. Used $ionicHistory.nextViewOptions({disableBack:true});. But in ios 9, randomly shows back button on nav bar.

please help me out in this. I worked hard to find the solution but i couldn't. Please suggest me. thanks