Windows APP without real internet connection stops working in time

Hello all,

I am trying to get the following to work. We have an intranet page which users need to connect to, to operate some machines. This is done through an windows 8.1 Tablet with an assigned KIOSK mode app (Kios SP Browser).

This works great as the assigned app is the only thing the user can run and we don't have to really harden the device. One drawback in using the assigned apps is that it needs to be an New App (as Microsoft call it)

The app is installed on an reference machine which runs in workgroup mode (no domain connection is needed on the devices) and after the reference machine is installed it is imaged with the use of Acronis. After deployment the tablet has no connection to internet and the intranet page is wireless put available to the tablets. As a side note, the tablet operates with local accounts and the app is installed using an corporate hotmail account we created just for this purpose.

I now deployed the image over 20 different tablet devices and this worked great until recently a few devices start to complain it needs to connect to the windows shop before the app can be started. As the devices don't have internet access this can't be done and the tablet is rendered useless for the user.

How can i make the app available without internet connection ? and how can i be sure the app will continue to work over time without connection to the store ?