MoodJot is a mood tracking app I built solo using Kotlin Multiplatform and Compose Multiplatform. It ships on both iOS and Android from a single codebase.

The main differentiator from existing mood trackers (Daylio, DailyBean, etc.) is a community feed where users can share moods and see how others are feeling.

Technical details: - Compose Multiplatform for shared UI (31 screens) - GitLive Firebase KMP SDK for Firestore, Auth, Storage - ChatGPT integration for AI mood pattern analysis via Ktor - expect/actual for StoreKit 2 (iOS) and Play Billing 7.0 (Android) - Home screen widgets: SwiftUI WidgetKit (iOS) and RemoteViews (Android) - Custom localization: 5 languages without platform string resources - Kamel for cross-platform image loading, multiplatform-settings for persistence

Other features: photo attachments, 10-point intensity scale, 80+ trackable activities, 25+ achievement badges, 14 emoji themes, goal tracking.

Live on App Store and Google Play since November 2025.

https://moodjot.app

Happy to discuss the KMP architecture or any design decisions.