This may not be important for most users, but to run "Code Factory Vocalizer version 3.x.x" after installation from .apk, there must be active at least one Google account on device.
For example, to run any iGO (Primo, NextGen, ...) apk or older "Vocalizer_e2.tts_1.0.2.3t2", it is not needed to have any active Google account on device.
Anyway this newer version uses about 357.5 MB less then previous with Croatian language installed.