Last year, Apple removed the App Store from iTunes. Soon after, however, Apple quietly released a special edition of iTunes that retains access to the App Store for "certain business partners" who "might still need to use iTunes to install apps."
Apple provides a download page on its website for the special edition of iTunes, which originally had a version number of 12.6.3. Two updates have since been released, including version 12.6.4 and the current version 12.6.5.
As brought to our attention by a MacRumors reader, and confirmed by our own testing, however, iTunes 12.6.5 fails to install on Mac systems updated to the public release of macOS Mojave this week. It also appears that the previous 12.6.3 and 12.6.4 versions do not function properly on macOS Mojave.
It's unclear if Apple does not plan on supporting the special edition of iTunes on macOS Mojave, or simply hasn't updated it yet. In the meantime, Apple Configurator can be used to mass-deploy apps on iOS devices from a Mac.