Z-Machine - makes playing classic Zork interactive fiction and graphical games possible and easy on Android devices.

Currently supports:
Zork I: The Great Underground Empire
Zork II: The Wizard of Frobozz
Zork III: The Dungeon Master
Beyond Zork: The Coconut of Quendor
Zork Zero: The Revenge of Megaboz
Return to Zork

Z-Machine is not the games themselves and does not contain or require any ROMs to play.
Z-Machine simply provides an interface to the publicly available Internet Archive posting of the streaming version of the games found here:
https://archive.org/details/msdos_Zork_I_-_The_Great_Underground_Empire_1980
https://archive.org/details/msdos_Zork_II_-_The_Wizard_of_Frobozz_1981
https://archive.org/details/msdos_Zork_III_-_The_Dungeon_Master_1982
https://archive.org/details/msdos_Beyond_Zork_-_The_Coconut_of_Quendor_1987
https://archive.org/details/msdos_Zork_Zero_-_The_Revenge_of_Megaboz_1988
https://archive.org/details/msdos_Return_to_Zork

This requires internet to load the games, but does not use any data after that.