Warning: Check your phone for unwanted "Sliide" intrusive full-page video spam

Recently I noticed an advertisement spam full-page popup on my phone.
That's unheard of for me (given how my phone is set up to never see ads).

The full-page video spam would pop up, but it would easily go away also.
The news-related spam had a "settings" gear icon but no "About" parentage.

Worse, it suspiciously didn't leave a presence in the "Iecently used".
Nor did it leave any leftover "Activity" presence in Android inspector.

Hmm...

Clearly it was written by a clever entity to hide its tracks well.
Who could be this clever intruder who makes it hard to identify parentage?

Digging about, I soon found the offensive full-page video activity was
 <com.sliide.content.MainActivity> (and yes, that's "sliide")

Apparently "Sliide" is a company that advertises directly to phones.
It was installed without my express consent, apparently, by T-Mobile.

But Sliide is, apparently marketing to *many* carriers.
(Is it marketing to the UK and EU carriers? I do not know if it is. Is it?)

Apparently Sliide's marketing to carriers is "Bigger revenue!".
 <https://sliide.com/carriers>
   "Sliide is at the center of the phone experience,
    allowing exceptional analytics and maximum monetization 
    of every click, tap and swipe in real time!"

Note that Sliide marketing focuses on *many* carriers (not just tmo).
 <https://sliide.com/> "Unlock digital revenue!"
 "Sliide lets you go to places on a subscriber's phone 
  that you couldn't get to before, offering custom content 
  you can monetize. It's brand-new incremental revenue!"

Yet, long ago I had adb wipe out all T-Mobile bloatware en masse.
Luckily, this "Sliide" T-Mobile spam can be deleted from Android Settings.

It was apparently re-installed on June 4th, 2025 (without my permission).
Besides popping up full-page ads, it has 7 trackers. It can open links.

It has a "Hidden API Enforcement Policy" of "Enforce (dark-grey and black
lists"), which is a good thing as it can't access Android blocklist APIs
nor conditionally blocked APIs (restricted by API level).

Still, I deleted it; & I would ask other tmo USA customers to look for it.
 <https://i.postimg.cc/vTrHTPB2/t-mobile-play.jpg>

If you are T-Mobile USA, do you have this app on your system?
 T-Mobile Play <com.tmobile.m1>

If you're on T-mobile USA, what do you plan to do about this package?
If you're on any other carrier in the world, check for "Sliide" activity.

It's a separate topic how to look for activities with "sliide" in the name.
(Which we can cover separately, if people feel that's a useful topic.)
-- 
On June 4th 2025 T-Mobile USA apparently added this package to my phone.
T-Mobile Play <com.tmobile.m1>
That package has a full-screen spam "Activity" of
<com.sliide.content.MainActivity> (and yes, that's "sliide") with a
"Hidden API Enforcement Policy" of "Enforce (dark-grey and black lists").

T-Mobile Play is a pre-installed app (often referred to as "bloatware")
that T-Mobile includes on many of the Android phones they sell. It's
designed to provide free, ad-supported video content (news, entertainment,
sports, etc.) to T-Mobile customers.