Because Pokémon Ash Gray is a ROM hack, you cannot simply download a game file and play it on your phone or computer immediately. It requires a specific setup process. Here is the standard procedure for a safe download:
Once you have your Pokemon Ash Gray 4.2.gba file and emulator: Pokemon Ash Gray Version 4.2 Download
Version 4.2 covers the story up to the Orange Islands saga and includes various bug fixes from previous versions. Because Pokémon Ash Gray is a ROM hack,