I don’t know what you mean by this. You just want to display without having any controls?
This is two questions in one: what UI to use, and what app to use.
For the most flexibility and support in the community, use a Main UI page. I don’t recommend Basic UI, because the text is small and difficult to read from a distance. It’s basic. HABPanel works well enough, but if you’re starting fresh I don’t see a good reason to choose it over Main UI.
For a wall-mounted tablet, the general recommendation is to use the HABPanelViewer app (which works with any webpage, not just HABPanel) or FullyKioskBrowser app.
I use HABPanelViewer, because you can set up an item in openHAB and send commands to the tablet to turn the display on and off. So, my HPV tablet is only on when I’m home and awake, and otherwise turns itself off to conserve energy. You just have to set the default URL to whatever openHAB UI you’re using, and then create rules to send commands to the app.
Note that HPV is no longer in development, but the 0.9.27 version is very stable.
I don’t know much about FullyKioskBrowser, but you can find discussion about it in the community.
The openHAB app works too, but I don’t think you can use it to control the tablet. I could be wrong about that.
Search for “thing status”. There’s lots of discussion in the community and docs.
Easiest solution is to have a rule that triggers on thing status and updates another item. Beyond that, I don’t know how to accomplish what you want to do. If I were concerned about the status of a thing, I would have openHAB send me a notification whenever it goes offline, or solve the problem of why it goes offline in the first place.