Play your favorite GBA, GBC and GB games on dual-screen Android handhelds, with a live companion on the second screen. Build your own game-stats, guides, and more.
Android 11+ · arm64 · GPL v3 · No ads, no accounts, never online
The game runs on the screen you open GBA Duo on. The other screen becomes a companion that reads your game's memory as you play and shows what matters.
Pick a companion pack for each game, or import one from a .zip. Every game remembers its own.
The pack's Lua script reads the game's memory several times a second, so the screen follows along as you play.
Tap through tabs, buttons and pages. The controller keeps driving the game whichever screen has focus.
A pack can switch pages when something happens in the game, like a battle page that opens when a battle starts.
9 slots per game, each showing when it was saved.
Kept per game, right next to its save states.
Hold R2 for 2x, 3x or 4x, picked in the menu.
Off, GBA Color, LCD Grid, Scanlines and Scale2x.
Flip A and B if they feel the wrong way round.
Press L2 or BACK in a game for the menu.
Party, bag pockets, trainer card, and a battle page with both Pokémon's live stats
Gold, date and time, stamina, held tool and rucksack, affection, Harvest Sprites' work
Hearts, items, world map with your spot, kinstone fusions, and each dungeon’s keys and progress
Energy and tanks, missiles, power bombs, every ability upgrade, and sector completion with maps
A pack is just a folder of plain files. If you can write a little CSS and Lua, you can build one for your favorite game.
manifest.jsonid, name, which gameslayout.jsonboxes, text, bars, tabs, pagesstyle.cssreal CSS: flex, grid, fontsmain.luaupdate() reads game memoryStraight from GitHub releases. Install a new APK over the old one and your saves stay put.
.zip files holding a GBA/GBC/GB ROM show up in the library and play directly. A zipped game shares saves and its companion pack with the unzipped copy.._ files next to ROMs no longer show up in the library.update() can return a ui entry (set / navigate / back), so the game itself can change pages — e.g. open a battle page when a battle starts and go back when it ends. See docs-packs/companion-pages.md ("Changing pages from update()").overflow: auto/overflow: scroll is now actually scrollable (previously only clipped content, with no way to reach the rest). Verified on real hardware.GBA Duo is completely free and open source under the GPL v3. No accounts, no paywalls, no “pro” version. If it made your handheld a little better, you can say thanks with a coffee.
Support on Ko-fiTotally optional. Every tip goes back into the project.