GBA Duo Companion Builder
Select your own supported ROM. Images and game text are extracted on this device once, then cached in a companion ZIP for smooth gameplay.
1. Choose your ROM
For custom companions
Package a prepared Studio project for its exact ROM.
Project input check
References to review
Checks selected files and exact ROM identity; it does not execute Lua or verify game behavior.
Your ROM stays on this device. Building does not upload ROM data.
Choose a ROM to start.
2. Import into GBA Duo Plus
Download the companion ZIP, import it in GBA Duo Plus, assign it to this ROM and reopen the game. The project JSON can be opened in GBA Duo Studio.
Download companion ZIPDownload Studio projectThe generated files contain images and text from your ROM. Keep them private. Share this builder kit instead.
Fire Emblem companion packs, built on your device
GBA Duo Companion Builder turns an exact supported ROM into a companion ZIP for GBA Duo Plus and GBA Duo Plus SS. Depending on the profile, companions include Units, Map, Talk, Growth and conditional Battle Analysis.
There are 30 supported profiles, including FE6, FE7, FE8, Project Ember, Sacred Echoes, Vision Quest and The Last Promise. Other ROM revisions need their own profiles.
How do I use a companion?
Choose your ROM, build locally, then import the downloaded ZIP through your game's Companion pack menu. Generated game images and text stay private. You can also create supported packs directly inside Plus or Plus SS.
Which emulator should I download?
GBA Duo Plus uses a second Android display. GBA Duo Plus SS puts the game and companion on one screen for phones, tablets and foldables.