You might sideload an Android app, or manually install its APK package, if you're using a custom version of Android that doesn't include Google's Play Store. Alternately, the app might be experimental, under development, or perhaps no longer maintained and offered by its developer. Until now, the existence of sideload-ready APKs on the web was something that seemed to be tolerated, if warned against, by Google.
This quiet standstill is being shaken up by a new feature in Google's Play Integrity API. As reported by Android Authority, developer tools to push "remediation" dialogs during sideloading debuted at Google's I/O conference in May, have begun showing up on users' phones. Sideloaders of apps from the British shop Tesco, fandom app BeyBlade X, and ChatGPT have reported "Get this app from Play" prompts, which cannot be worked around. An Android gaming handheld user encountered a similarly worded prompt from Diablo Immortal on their device three months ago.
Google's Play Integrity API is how apps have previously blocked access when loaded onto phones that are in some way modified from a stock OS with all Google Play integrations intact. Recently, a popular two-factor authentication app blocked access on rooted phones, including the security-minded GrapheneOS. Apps can call the Play Integrity API and get back an "integrity verdict," relaying if the phone has a "trustworthy" software environment, has Google Play Protect enabled, and passes other software checks.
Graphene has questioned the veracity of Google's Integrity API and SafetyNet Attestation systems, recommending instead standard Android hardware attestation. Rahman notes that apps do not have to take an all-or-nothing approach to integrity checking. Rather than block installation entirely, apps could call on the API only during sensitive actions, issuing a warning there. But not having a Play Store connection can also deprive developers of metrics, allow for installation on incompatible devices (and resulting bad reviews), and, of course, open the door to paid app piracy.
...as I upvote you from my Pixel. ☹️ I give the sad face because Google isn't who they once were and I'm just going to have to deal with that.
Never ask a company to pick between the right thing and profit. It was all a matter of time till Google needed to stop growing and start producing profit for investors.
To make it worse the Pixel 9 starts at $800 just like iPhone. So if you're buying Android you don't really save money over an iPhone like you used to.
It's fundamentally impossible for a publicly traded company not to choose profit over 'The Right Thing', fullstop. Shareholders feel that have a fundamental right to growth, and if Google's CEO were to choose 'The Right Thing' over profit, the shareholders can oust them in favor of a CEO willing to choose profits.
Enshittification is where every public company ends up, because the line MUST go up, no other alternative is acceptable.