Some apps claim to randomize ROMs on-device, but they often crash with Emerald. The most reliable is Randomizer for GBA (available on GitHub or F-Droid). It works, but options are limited compared to the PC tool.
Use your Android browser to search for "Pokemon Emerald Randomizer pre-patched GBA ROM." Look for community threads on Reddit (r/PokemonROMhacks) or PokeCommunity forums. Avoid pop-up-heavy sites. Some known safe archive names include: pokemon emerald randomizer download gba rom android
Use an app like ZArchiver or RAR from the Play Store to extract the .gba file from the .zip folder. Some apps claim to randomize ROMs on-device, but
Pro tip: Enable save states (in-emulator) so you don’t lose progress when you encounter a ridiculously overpowered trainer. Use your Android browser to search for "