Read update
- Now available on the Play Store
Behaviors found in both Android and the Microsoft Teams app led to a frightening situation recently where someone was prevented from making a 911 call on their phone. While Microsoft has a patch for its app, Google won't have a fix on the OS level until January 4 at the earliest. In the meantime, it's entirely possible that another app may have the same faulty behavior that Microsoft Teams did, potentially preventing other Android users from reaching emergency services. If you're concerned about this possibility, there's a new app to help you check.
The app is from XDA contributor linuxct (who has some more fun projects in their portfolio) and is hosted on GitHub along with its source code — you can download the pre-assembled APK from this page.
In essence, PhoneAccount Abuse Detector is simply meant to find apps that do what Microsoft Teams did: generate an enormous number of registrations as a phone client (known as a PhoneAccount) to Android. The more clients the operating system is given to sort through when an emergency call request is made, the more likely it is to freeze up. You can find a fuller explanation of the issue from my colleague Ryne Hager, too.
PAAD requests permission to access and manage phone call data. It then shows a topline result of whether any apps have the problematic behavior followed by the full list of telephony apps on your device and how many instances of PhoneAccount they've made. In most cases, any amount more than one should raise a flag. You can then take action with the information you now have.
Again, the behavior has been patched out of Microsoft Teams and an OS-level security update will fix it for all other possible apps starting January 4 — though your mileage may vary on when it actually gets passed onto you.
UPDATE: 2021/12/15 12:03 EST BY JULES WANG
Now available on the Play Store
In case you were wary of sideloading an app from GitHub with all of its source code available for inspection, you can now download the app from the Google Play Store which has done the work of making sure nothing bad is in there.