If you really want to disable that Guided Access pop-up message, I think there's a way to do it. It's called "Single App Mode". You use Apple's Configurator to enable it through a configuration profile, and it literally locks the iPad into booting directly into that app, and you cannot disable it without connecting the iPad to (presumably the same?) computer and removing the profile.
The downsides are:
1. You have to put the iPad into supervised mode, which requires a full factory reset through the Configurator. This is because it enables a bunch of enterprise controls that they don't want enabled without the user's knowledge, such as the ability to configure a global HTTP proxy, etc.
2. As I mentioned before, there is literally no way out of the app other than removing the configuration profile. This sounds like it interferes with your use case, but maybe it's a worthwhile tradeoff for you?
3. Probably something else I didn't think of.
Here are a couple articles I found that mention how to do this:
[0] and [1] are articles from some app that this feature is useful for, explaining how to do it for that app.
Disclaimer: I have never tried this myself, I have simply happened to have heard of it. I found the two articles above because I knew the term to Google (not a shot at you, sometimes you just need to know the right search). There may be some unintended consequences because it's an enterprise feature and all.
Another way to address the original problem is jailbreaking and using the Activator app to assign the home button to "unlock", which effectively auto-unlocks the device to whatever app you had open.
I find it quite a usability improvement, when using the tablet as a cookbook for example.
The downsides are:
1. You have to put the iPad into supervised mode, which requires a full factory reset through the Configurator. This is because it enables a bunch of enterprise controls that they don't want enabled without the user's knowledge, such as the ability to configure a global HTTP proxy, etc.
2. As I mentioned before, there is literally no way out of the app other than removing the configuration profile. This sounds like it interferes with your use case, but maybe it's a worthwhile tradeoff for you?
3. Probably something else I didn't think of.
Here are a couple articles I found that mention how to do this:
[0] and [1] are articles from some app that this feature is useful for, explaining how to do it for that app.
[0]: http://support.kioskproapp.com/knowledgebase/articles/413366...
[1]: http://support.kioskproapp.com/knowledgebase/articles/315259
Disclaimer: I have never tried this myself, I have simply happened to have heard of it. I found the two articles above because I knew the term to Google (not a shot at you, sometimes you just need to know the right search). There may be some unintended consequences because it's an enterprise feature and all.