[Samsung Galaxy Tab A series Questions & Answers] dragontology:
So, at work we have a fleet of SM-T580s, and they're set up with some custom software. No lock screen, for instance. When the thing boots up, it asks for a password, which we all know, I guess it's just so they can't be used if stolen. Once you enter that, it does the "unlock icon" and alternating green/blue circles animation, then it loads an app, there's a toast that says "App Pinned," and from there... you can't access the Android system underneath.

A few weeks ago, I accidentally got out of that and into Android settings. Turns out Developer Mode was already unlocked, so I disabled the app animations. Made the tablet a bit faster, because Android animations are kinda BS, especially on an older (2016) tablet with 2GB of RAM. The animations are, at best, unnecessary. Well, now we have one "super" tablet that everyone covets, and the rest are just kinda crappy.

IT is in another state and doesn't care what we think about the tablets. All they're for is for scanning inventory in a warehouse. It's not even a named app, it's just something someone put together. It even has (slow AF) animations that aren't disabled by disabling animations, they're baked right into the app. (I guess someone thought they were being cute. They failed.)

Anyway... I know all about screen pinning, and how you un-pin an app by holding Recents and Back for five (ten?) seconds. That doesn't work. Once the company's custom app loads, there doesn't seem to be anything you can do. The home button does literally nothing. Same with Recents. Back will cancel a barcode scan, but otherwise, also does nothing. The volume keys work, and the power button turns off the screen. There's no lock screen, pressing power or home just turns the screen right on.

I've been trying to figure out how I got into Android Settings before. I think it was something with the recent button, before the app was able to load. Basically, my coworkers want me to disable animations on the other three or four dozen T580s we have so everyone has a "good" tablet. I've told them it was probably a fluke and showed them what I did and when/where to do it, but nobody has been able to recreate my success.

I've looked all over Google, but it seems like there's only one kind of app pinning. So, I come to XDA... Can custom ROMs use a kind of "super" app pin, like a kiosk mode, that can't be unpinned? I'm wondering if there's a secret sequence that can allow one to exit out. I assume the company does its work over ADB... a few of them have the "4.4" version of the company software, while the rest have the newer "4.7" version (these are not Android versions as the tablet is running Lollipop or newer; I understand the thing came with Marshmallow, so, probably that). So they can't even be bothered to update all their tablets to the latest version of their own software. Not very competent if you ask me.

And of course, I'm fully aware that "other people's" phones/tablets shouldn't be tinkered with. That said, I think we can all agree that disabling app animations in Developer Options is 100% harmless. Many custom ROMs either reduce the animation speed to half or 25% or disable it entirely to make the phone or tablet seem "faster." In most cases, it's not faster, but these slow tablets with old batteries that need to be rebooted several times a day do perform better with app animations disabled. If only slightly better.

Lastly, I realize that having been outside of the "app super pinning" environment, the very first thing I should have done was examined the list of apps and looked for the app doing the pinning in the first place, and looked for its escape sequence, assuming one exists in that app's settings, and that app isn't password protected. Instead I just said, "hey, I'm in settings, I'll just disable the app animations to make it run faster and that'll be cool."

It's odd that, when it boots up, settings is reachable via the recents key. When an Android tablet turns on, it should have no apps in recents, right? iOS keeps apps in memory through reboots, but I don't think Android does, or at least I don't think Android did in the Marshmallow days. This thing might be 100% custom, but I've never heard of a private company making custom firmware that changes things like what the system buttons do. Though, I suppose it's at least possible.

Thanks in advance if you can help us out.