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 ...