The latest articles on DEV Community by Sangid Duha (@sangid_duha). https://dev.to/sangid_duha https://media2.dev.to/dynamic/image/width=90,height=90,fit=cover,gravity=auto,format=auto/https:%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Fuser%2Fprofile_image%2F4144248%2F5d87bda0-e333-4594-abbd-f5ba9eaed62c.jpg https://dev.to/sangid_duha en Sangid Duha Sat, 26 Sep 2026 11:58:09 +0000 https://dev.to/sangid_duha/how-i-built-an-offline-first-time-tracking-invoicing-app-for-freelancers-420g https://dev.to/sangid_duha/how-i-built-an-offline-first-time-tracking-invoicing-app-for-freelancers-420g <p>Lessons learned building HourBill from scratch (and ditching subscriptions).</p> <p>I couldn't find a simple, offline time tracker that easily exported PDF invoices without a monthly subscription...</p> <p><a href="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Farticles%2Fjhomna7hbz9ne27iyatk.jpg" class="article-body-image-wrapper"><img src="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Farticles%2Fjhomna7hbz9ne27iyatk.jpg" alt=" " width="800" height="447"></a></p> <ol> <li>The Problem: The frustration with existing tools (subscriptions, forced accounts, cloud-only dependency).</li> <li>The Solution: Introducing HourBill.</li> <li>The Tech Stack: Mention Kotlin, Room, Material 3, and Firebase. Explain why an offline-first architecture was chosen.</li> <li>The Hardest Part: Share one technical challenge you faced (like the Foreground Service timer surviving battery killers) and how you solved it.</li> <li>Call to Action: "HourBill is live! You can check it out here: <a href="https://play.google.com/store/apps/details?id=com.ssstudio.hourbill&amp;hl=en" rel="noopener noreferrer">Google Play</a>."</li> </ol> freelance timetracker programming androidapp