Well, after a couple insightful comments, such as "doesn't work" and "waste of time", it's clear there are a few too many recent users that aren't grasping you have to enable the main switch for the launcher to appear.
Now you can't exit the app when it's disabled without first being warned about it. I'd love to say it was because the process was too elaborate, but the reality is that you can't simplify things enough for some.
That's an odd choice of question. I typically don't sabotage my apps, but I do usually include a way to submit or retrieve logs in them. This one is no different. The top right button labeled "Support" does exactly that.
Keep in mind, I cannot enable the permissions on your behalf and you will not find the app in the cover screen widget list. These are two of the biggest reasons for most reports that the app will not open.
Welcome to the original Z Flip 3 launcher.
A complete home experience on the cover screen.
This is the next innovation in cover screen apps. After pioneering the widget launcher, this app has evolved into a full parallel launcher and continues to revolutionize the cover screen.
This launcher adds cover screen support for full notifications with actions, apps, widgets, quick toggles, voice launch, custom screen timeouts, animated wallpapers, and more.
TooUI began and remains the only cover screen app to fully integrate with the stock launcher, bypassing the limitations of the widget interface or attempting to replace the existing home functionality.
In all fairness, I don't think i've explained why the limitations are what they are and should probably have done that a while ago.
The cover screen is effectively like plugging in a second screen on a previous S or Note series phone. DeX is effectively a secondary home launcher. Since this screen is part of the phone, instead of connected by a cable, a second launcher is used instead of DeX.
The outer screen supports a second launcher, such as Nova or Smart Launcher 5. It also supports a primary launcher having a secondary launcher activity. Samsung, on the other hand, has disabled this support in favor of a hardcoded launcher that's built into the firmware.
Samsung's launcher has been broken into the home screen, which is the clock selection, and widget pages. It's been further limited by only allowing certain widgets to be available on the widget pages.
Being a system app signed by Samsung, they've gone a step further. The widgets allowed must system apps or signed by Samsung, as well. One loophole exists, which is Samsung Health. It does not need to be a system app, since you can install it from Google Play. It also doesn't need to be signed by Samsung for whatever reason. It does, however, still need to match up with the expected widget inside the expected app.
This app takes advantage of the loopholes by using the specific component name (package / package.activity) of the Samsung Health widget and the package for Samsung Health. Because of this, the app must also be a widget, though. It cannot be a full launcher.
Widget functionality is limited, but can support launching apps. This is another loophole that uses the widget list support to act as a fake launcher. Since the core launcher behind the widgets is still a launcher, it will launch apps on the cover screen.
Like a normal Android screen, configuration changes are handled by the current activity being displayed. In this case, that would be whatever app is launched. The widget gets taken along for the ride. To minimize the impact of the launched app, the widget is designed to ignore any configuration changes, which would usually trigger the list to refresh.
A few unique problems exist because of the cover screen being composed of widgets. One is that they do not follow the expected life cycle of a widget. They are not refreshed when they appear, which is why a swipe is sometimes needed to make list items clickable. Another is that they cannot perform any of the prep an activity provides, such as handling the lock screen. When an activity requests overriding the lock screen, it only extends to the activity and not to any it launched.
This leaves us with what you see. A widget that exploits a bunch of loopholes within the limitations of the widget framework.
Widgets on the cover screen are granted Settings.canDrawOverlays without the need for permission approval from the user?
With the option off in the app settings, the app never requested the permission and instead simply verified that it was already granted. That is interesting...
and now the big news:
Portrait apps may now be fully functional, if my testing is correct.
The permission approval button when launching the app from the drawer shouldn't be required, but it exists in case it will help with any finicky apps / devices. It will request system settings and overlay permissions.
System settings permission will allow the widget to temporarily disable the automatic rotation option, while the overlay permission creates a fake view over the widget that is locked in portrait and steals focus from the widget to avoid it forcing the layout back to landscape. This will not, however, prevent apps with landscape support from functioning normally.
A new caveat I found is that, when charging, tapping power and waiting won't exit the current app. I do not intend to address this right now. The reason being that the controls to have the power button return to the widget also force a screen timeout to return to the widget and can cause issues with the app being displayed when opening the phone.
A quick and dirty workaround to change apps when charging is to simply open the phone a bit. This will reset the widget without breaking the expected functionality.
As it stands, the power button and a timeout will not kill the current app unless they exceed two seconds and will not kill the app at all when charging. This allows long-term use of a single app, which fits most use cases. Other options to switch apps, such as volume button overrides, are also being explored.
@ChrisChoi314 it appears your list of incompatible apps was lost in the cleanup. If you still find any, you can post the list on the issue for it.