Here is a cheap little project I did at home, using an old Android tablet I had laying around and a cheap box photo frame and a long white USB cable for powering the tablet.
I am using the excellent ImperiHome Android app which can be used to control various Z-Wave gateways such as Vera and the Fibaro Home Center 2 and some others.
With the ImperiHome app I can control all aspects of the home automation system such as lighting, curtains, heating etc however the main use for this wall panel will be for entry and exit. To be able to arm and disarm the house / Z-Wave alarm system.
ImperiHome has a very useful feature and this is the ability to lock down certain scenes or devices with a pin code. So for example when I press the Welcome Home scene or the Disarm House scene you are prompted to enter a 4 digit pin code like a traditional alarm panel.
Another nice feature of ImperiHome is the screensaver option, so after a set amount of time, 1 minute in my case the screen will go black / dark.
I have configured the Android tablet to never go to sleep so it will always be on and the WIFI will always be up and running, you just need to tap the screen once to display the ImperiHome app and away you go you can then control the home automation system instantly.
ImperiHome also has an option to start the app at startup. so if the tablet loses power or is restarted the ImperiHome app will automatically launch again.