I shipped GoGBA (Android + iOS) to both stores in late December 2025. Six months in: MAU peaked at 8.3k, currently steady around 7.4k. No paid advertising, ever.
This is a write-up of what the six months actually involved. I'll be specific about the technical work, and equally specific about the mistake that cost me RetroAchievements hardcore certification — because that part is the most useful thing here for anyone building in this space.
Why GBA only
I grew up on a GBA — Super Robot Wars, Fire Emblem, Pokémon, Castlevania, Zelda. Later NDS/3DS/PSP/Vita/Switch arrived and the GBA did its job and retired. On PC the emulator I remember is VisualBoyAdvance.
I've used GBA, NDS and PSP emulators on phones. I kept coming back to GBA, for four reasons that are all practical rather than nostalgic:
