Mobile Project Management App with Offline Synchronization

A manager jots down tasks in a notebook during a meeting, then transfers them to Trello—by then, colleagues are already working with outdated data. Our solution: a mobile app with offline-first synchronization that instantly syncs changes even without internet. We develop for iOS and Android, backed by 30+ projects and a 3-month warranty. Key features: Kanban, push notifications, time tracking, and Gantt chart.

Problems We Solve

Offline editing conflicts. Two users change a task status without network. We apply Last-Write-Wins with timestamps; for complex scenarios, we use Operational Transformation (as in Notion). This prevents data loss with 1000+ concurrent users.

Intrusive push notifications. Constant alerts reduce productivity. We implement contextual logic: @mentions immediately, assignments immediately, deadline changes to the assignee, deadline within 24 hours—reminder. Users customize notification types in profile—settings sync across devices. According to our stats, this boosts retention by 25%.

Mobile Kanban. Drag-and-drop between columns is technically tricky due to gesture conflicts. Our approach: tap → bottom sheet (Android) or context menu (iOS) to select status. Simpler but reliable on any device. On iOS we use UIContextMenuConfiguration (iOS 13+), on Android—ItemTouchHelper with simplified D&D.

How We Do It

Typical architecture: Workspace → Project → Board → Task → Subtask → Comment. Local storage: Room or Core Data. Server sync via REST/GraphQL. Our approach to pricing is transparent: we estimate after analyzing your requirements, so you only pay for what you need.

// Android — pending operations queue class TaskRepository( private val taskDao: TaskDao, private val pendingOpsDao: PendingOperationDao, private val api: ProjectApi ) { suspend fun updateTaskStatus(taskId: String, newStatus: TaskStatus) { taskDao.updateStatus(taskId, newStatus) val op = PendingOperation( type = OperationType.UPDATE_TASK_STATUS, entityId = taskId, payload = json.encodeToString(mapOf("status" to newStatus.name)) ) pendingOpsDao.insert(op) if (networkMonitor.isConnected) syncPendingOperations() } } 

For iOS—similar with Core Data and NSBackgroundActivityScheduler. Smart push notifications subscribe via APNs/FCM; filtering logic lives on the server.

Why Push Notifications Shouldn't Be Annoying?

Constant notifications break focus. We implement a priority system: high—@mention, task assignment, deadline change; medium—status changed (only for watchers); low—scheduled reminder 24 hours before deadline. The client stores settings in the server-side profile, so they persist after app reinstall. This improves retention and keeps users happy.

Gantt Chart Implementation Approaches

We recommend native rendering for projects with hundreds of tasks—it ensures smooth scroll and zoom, though it requires more development time.

What's Included in the Work

After project completion, you receive:

• Source code under NDA;
• Architecture documentation (diagrams, stack description);
• Configured CI/CD (GitHub Actions + Fastlane);
• Access to App Store Connect and Google Play Console;
• Team training (2-3 sessions);
• 3-month warranty for defect fixes.

Timelines

MVP (tasks, Kanban, push, offline): from 8 to 12 weeks. Full set: 16–20 weeks. Interested in an estimate for your project? Get a consultation—we'll provide details tailored to your stack.

How to Ensure Conflict-Free Synchronization During Offline Work?

The key is a pending operations queue with idempotency keys and a retry mechanism. On the server—validate changes by entity version (optimistic locking). On the client—show sync status (green/yellow/red icon). This way users know the state of their data. We use this approach in all projects—proven under load up to 1000 concurrent users. We guarantee stable operation thanks to our experience with high-load systems.