Adversaries may seek to identify all applications installed on the device. One use case for doing so is to identify the presence of endpoint security applications that may increase the adversary's risk of detection. Another use case is to identify the presence of applications that the adversary may wish to target.
On Android, applications can use methods in the PackageManager class  to enumerate other apps installed on device, or an entity with shell access can use the pm command line tool.
On iOS, apps can use private API calls to obtain a list of other apps installed on the device.  However, use of private API calls will likely prevent the application from being distributed through Apple's App Store.
|S0316||Pegasus for Android|
|S0539||Red Alert 2.0|
Triada is able to modify code within the com.android.systemui application to gain access to
Application vetting techniques could search for use of the Android PackageManager class to enumerate other apps, and such applications could have extra scrutiny applied to them. However, this technique may not be practical if many apps invoke these methods as part of their legitimate behavior. On iOS, application vetting techniques could similarly search for use of the private API call necessary to obtain a list of apps installed on the device. Additionally, on iOS, use of the private API call is likely to result in the app not being accepted into Apple's App Store.