Dayce

A Flutter app for managing schedules and diary entries by date in one place

Built for 2026 NE:XT CONTESTKorea University College of Informatics · 2026.03 – 2026.05

Period: 2026.03 – 2026.05
Type: Solo project
Team: Solo
Role: Solo developer (planning and development)
Status: Completed
Deployment: Download AvailableGitHub Releases

Language: Dart, see projects using this technology
Mobile: Flutter, see projects using this technology
Database: SQLite, see projects using this technology

AI ToolsClaude Code

Demo video Android APK (Dayce 1.0.0)2026 NE:XT CONTEST page

See All Screens (7)

GitHub Repository

gaudium1257/2026320053_NEXTCON (new tab)

Summary

A Flutter mobile app for managing schedules and diary entries by date in one app. It was built solo through vibe coding with Claude Code and entered in 2026 NE:XT CONTEST, the software competition of Korea University’s College of Informatics. It offers day, week, month, and year calendar views, recurring and multi-day events, and diary entries with a mood emoji, and stores all data in on-device SQLite.

What I Did

Built the entire app through vibe coding with Claude Code
Planned a service combining schedules and diaries and defined its features
Fixed screen layouts that overlapped the system navigation bar
Produced the demo video and wrote the contest proposal and report

Screens

Phone screen Month view for May 2026 with multi-day and recurring events

Phone screen Long-pressing and dragging to select May 11–14

Phone screen Event form filled in with the selected range

Phone screen Day view for May 31 with an all-day banner and timeline

Phone screen Sheet for choosing whether to add an event or a diary entry

Phone screen Diary form with a mood picker

Phone screen Warning shown when leaving without saving

Key Features

Day, week, month, and year views: Switches between four views and moves through dates by swiping.
Event management: Adds, edits, and deletes events with a title, date and time, all-day option, memo, and color.
Recurring events: Supports daily, weekly, monthly, and yearly repeats with a repeat end date.
Multi-day event bars: Shows overlapping multi-day events as bars on separate rows of the weekly grid.
Drag to select a range: Long-pressing and dragging across dates opens an event form filled with that range.
Day timeline: Shows all-day events as banners and timed events on a timeline, placing overlapping ones side by side.
Daily diary: Writes one entry per day with a mood emoji and warns before leaving without saving.
Diary list: Groups entries by month and narrows them with month filters.
Settings: Saves the default view, week start day, default event color, ruled-line background, and default mood.

Tech Stack

Language

Dart: The Flutter app’s code

Mobile

Flutter: Day/week/month/year calendars, event and diary forms, the diary list and settings screens

Database

SQLite: Stores events and diary entries on the device (sqflite), with DB version 1→3 migrations

Other projects using the same technologyGUDORY Local Quest Hello Vibe

Architecture

Flutter screens read and write on-device SQLite and the settings store directly through DatabaseService (sqflite) and SettingsService (shared_preferences). The app uses no server or external API.

Problems & Solutions

Problem
App screens overlapped the system navigation bar
Solution
Turned off Android edge-to-edge and applied SafeArea to the form and settings screens

Outcomes

Entered in 2026 NE:XT CONTEST
Produced a demo video and published it on YouTube
Published an Android APK (Dayce 1.0.0) on GitHub Releases

Learnings

My first app project and my first time using Flutter and Dart
Experienced firsthand that vibe coding can produce a working app without prior knowledge