The app ID is com.google.android.verifier, which I assume will be used for the upcoming developer verification program for installing 3rd party apps.
Starting September 30, developers (signing authors) need to be verified from Google to distribute apps in the following app stores:
- Google Play Store
- Honor App Market
- OPPO App Market
- Samsung Galaxy Store
- Transsion Palm Store
- vivo V-Appstore and
- Xiaomi GetApps
only in the countries of Brazil, Indonesia, Singapore and Thailand.
F-Droid is not included for this time.
It is planned to be rolled out globally across all markets/app stores by January of 2027.
Relevant sources:
https://developer.android.com/developer-verification/guides
https://keepandroidopen.org/
I used App Manager (io.github.muntashirakon.AppManager) for the screenshot; you can use your regular 'Installed Apps'/'Apps' menu to see if it's been rolled out automatically for you as well.
edit: First link was originally a typo, my bad. Fixed it.
After going through both my Galaxy 24U and Pixel Tablet initially, I wasn't seeing the option (was looking for the old "Install from unknown sources" which is in a different location (and per app toggles). I went back and manually disabled and enabled the "Android Developer Verifier" app and then saw the option for "Apps from unverified developers" show up. Then was able to follow the steps (very glad you provided that second source which is what led me to what I did).
So I guess if you don't see it. First search in your apps that the verifier app is present. If it is, then go into the app info for it and toggle disable and then enable. Willing to accept that maybe I was just blind to it due to the old way of sideloading that made me miss it in Developer Options. But for sure saw it after the toggles. Now I just need to remember to go back tomorrow to set the "indefinitely" option. Curious if this will allow Play Protect to not try to yeet apps if PP is turned back on. I had to turn it off a couple months ago because it kept flagging SyncThing-Fork installed from F-Droid trying to trick me into uninstalling it (which was weird that was the only app it freaked out about out of all the third-party store and Obtainium apps).