How I Built an Offline-First Time Tracking & Invoicing App for Freelancers

Lessons learned building HourBill from scratch (and ditching subscriptions).

I couldn't find a simple, offline time tracker that easily exported PDF invoices without a monthly subscription...

1. The Problem: The frustration with existing tools (subscriptions, forced accounts, cloud-only dependency).
2. The Solution: Introducing HourBill.
3. The Tech Stack: Mention Kotlin, Room, Material 3, and Firebase. Explain why an offline-first architecture was chosen.
4. The Hardest Part: Share one technical challenge you faced (like the Foreground Service timer surviving battery killers) and how you solved it.
5. Call to Action: "HourBill is live! You can check it out here: Google Play."