Sortive

Overview

Sortive is a productivity and personal finance app I designed, built and published to Google Play. It combines task management, an hourly day planner, rich-text notes and expense tracking, with a dashboard pulling the four together.

The problem

I wanted one app covering tasks, planning, notes and money, that worked with no connection and still synced across devices. Most apps do one of those two things well and treat the other as an afterthought.

What I built

Task management with categories and status, an hourly day planner with sub-tasks, a rich-text notes system, expense tracking with income settings and categories, and a dashboard pulling all four together. Local-first storage in Isar so the app is fully usable offline, with Firebase Authentication and Cloud Firestore providing sync across devices and per-user data isolation.

Built in Flutter as a monorepo: the application plus separate shared packages for core logic and the UI system, with Riverpod for state and go_router for navigation.

Complexities tackled

Two-way sync is where offline-first projects die. Offline-first inverts the usual direction: the local database is the source of truth and the cloud reconciles to it, which is the opposite of what most SDK examples assume. Getting bidirectional sync right, so that edits made on two devices while both were offline merge sensibly rather than one silently overwriting the other, took several passes and is the single hardest thing in the app.

Local schema changes are permanent. With a cloud database you migrate the server. With an on-device database, every user is running whatever version they last installed, and a careless schema change means data loss on someone’s phone. Local models have to be treated as a published contract.

Splitting the packages before I needed to. Core logic and the UI system were extracted into their own packages early, which felt like overhead at three screens and is the reason features stayed quick to add at thirty.

Four apps in a trench coat. Tasks, planner, notes and expenses each want a different data shape and a different interaction model, and the dashboard has to make them feel like one product rather than four tabs.

Stack

Flutter, Dart, Isar, Firebase Authentication with Google Sign-In, Cloud Firestore, Riverpod, go_router, flutter_quill, local notifications.