Building 24 iOS Apps as a Solo Developer in Japan

Hey Indie Hackers! 👋 I'm Keisuke, a solo iOS developer based in Japan. I've been building and shipping iOS apps for several years, and I wanted to share my journey of creating 24 apps while working alone.

The Portfolio

My apps span multiple categories:

Productivity

HieroNote - Hierarchical note-taking with built-in music player. Think WorkFlowy meets Spotify.

Games

Idle Spirits - A meditative block-breaking game where you collect 57 mystical spirits. No competition, just zen.

Health & Fitness

MyDailyEats - Food diary without calorie counting. Just categories and portion sizes.
PMS Rage Tracker - Because sometimes you need to track the anger, not just the cycle.

Pet Apps (AnimalScale series - 14 apps!)

Photo diaries for pet owners: BunnyScale, HamsterScale, CatScale, DogScale, and 10 more species.

AI-Powered

KidsPlayAI - AI suggests nearby playgrounds and activities for kids
LivabilityAI - AI analyzes neighborhood livability

Tech Stack

Swift + SwiftUI (100% native)
CloudKit for sync
No backend servers (cost = $0)
AdMob + StoreKit for monetization
35 languages supported via custom localization

What I've Learned

Niche beats general - My pet weight tracking apps found dedicated users who love their specific animals.
Privacy sells - "No account required, data stays on your device" resonates with users.
Less is more - MyDailyEats succeeds by NOT counting calories. The "missing feature" became the selling point.
Localization matters - Supporting 35 languages opened up markets I never expected.

Current Challenges

Marketing is hard for a solo dev
App Store discovery is basically zero without effort
Balancing maintenance of 24 apps with new development

What's Next

Launching on Product Hunt (preparing for this)
Building community around the apps
Exploring ways to monetize without compromising the user experience

Happy to answer any questions about building multiple apps solo, the Japanese iOS market, or anything else!

🔗 Links:

HieroNote: https://keik.co.jp/hieronote/index-en.html
Idle Spirits: https://keik.co.jp/idle-spirits/index-en.html
MyDailyEats: https://keik.co.jp/mydailyeats/index-en.html