Limit access to the AAC app in iOS 6

Install iOS 6 (released Sept. 19) and you can finally put your iPad into "single app mode" by disabling the Home button. This mode is officially called Guided Access. In addition, Guided Access allows you to disable selected areas of the screen. (I have used this feature in TouchChat and Proloquo apps to disable the backspace button for students prone to backspace and erase a constructed message before delivering it to their partner)

Full disclosure: The info and images below are pasted from an ASHA Community SIG 12 discussion via Bruce Engholm of Kingston, NY, originally retrieved from http://www.imore.com/how-use-guided-access-put-your-ipad-or-iphone-guest-user-mode Thanks Bruce!

How to turn on Guided Access

1. Launch Settings.
2. Tap General.
3. Scroll down and tap Accessibility.
4. Scroll down and tap Guided Access.
5. Toggle Guided Access to On.
6. Set a Passcode you'll remember. If you don't set a Passcode immediately, iOS will have you set one the first time you use Guided Access.
7. Triple click the Home button while in the app of your choice to turn Guided Access on. Triple click Home again to turn it off by choosing the option at the upper left of the screen, "End."

Be aware - this fantastic addition to iOS occasionally works too well! 
At times, the required triple click of the Home button, while in Guided Access, does not do anything, and then you're really stuck in the app. This leaves you unable to leave Guided Access mode, but here’s a workaround to get out of it until the bug is resolved:

• Hold the Home and Power button together for 15 seconds until a reboot is forced on the iPad, iPhone, or iPod touch
• With the device rebooted, go back to Settings > Accessibility > Guided Access > and turn OFF as necessary

Because just about everything is disabled when the feature is on, even Force Quit won’t work. Yes that means you’ll have to reboot the device in order to escape from Guided Access in certain apps for the time being.
The stuck app bug doesn’t appear to impact any native Apple apps, but it does affect many popular third party apps. Expect a resolution soon that doesn’t involve rebooting with iOS 6.0.1 or a similar incremental update.