can the app TMX or any other not well known third party app damage or hack your xbox one...

And that’s what I’m gonna do

You don't have to worry.

Every app that you get from the official Xbox store has been reviewed and certified by Microsoft to not damage your equipment. Otherwise the app wouldn't get a certification label and be removed from the store.

However, when you enabled Dev Mode on the console and sideloaded an unsigned app, things might be different. But even then: Apps are only running in a restricted virtual machine environment, and doesn't have direct access to anything hardware related.

So even if there were a malicious app around, it would be confined to very limited resources inside a virtual machine. So there is always that virtual machine layer that prevents rogue apps from causing actual damage to something "outside" it's system defined
sandbox confinement.

So don't think of apps on your Xbox as programs or viruses on your PC, where each program can directly run on the hardware.

Apps on the Xbox are actually complete virtual PC machines, that have only one purpose: Running this one app they belong to. So you could imagine the Xbox having lots of single purpose PCs stored on a shelf that only run one single app and nothing else.
And the main Xbox system can only run one main game app, and one background app (like the edge browser, or music player or the likes).

If you start an app or game, the Xbox takes that PC for the app from the shelf, starts that PC and lets it do its thing only on that virtual PC it's intended for, without being able to access anything "outside" that virtual PC.

So an app can't constantly run in the background, because it'd be displaced by the next app you'd launch. And the way those virtual machines are handled, if an app is displaced, the virtual machine running the app is shut down. Similar to pressing the power
button on your PC. The Xbox pulls the plug and puts the App-PC back in the shelf where it can't do anything at all.

Hope I could clear up your concerns 😊

Hello ValveChief,

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Hey man thank you so so much for your response to my post, back in December when I first had this fear it was really difficult especially when my impulsiveness got the Best of me but now I feel a little bit more confident to use my Xbox The only thing
I guess I’m having problems with is just getting it fully through my head since this is a bad habit that’s been going on since October when it comes to technology and stuff that I am currently seeking out therapy in order to remove but aside from all that
thank you so much for your reply

I would advise staying away from any 3rd party app and using it on your Xbox.