We build and ship software.
Haltansu is a small software studio. We shipped BillKaro (offline billing for small shops), Bloom (a privacy-first cycle tracker), and the free Developer Playground. Client work gets built the same way — by the people you actually talk to.
Shipped.
Apps we designed, built, and put in people's hands.
BillKaro
Offline invoice and billing app for small shop owners in India. Invoices, customers, and stock — all on the phone. Works with zero internet, because shop counters don't always have it.
- 100% offline — data never leaves the phone
- Invoices, customers, inventory
Bloom
An offline-first menstrual cycle tracker. Periods, symptoms, moods, and notes — stored only on the device, by design. No account, no cloud, no data sharing.
- Offline-first, on-device storage
- Cycle, symptom & mood logging
What we take on.
Two services. If your project isn't one of these, we'll say so — and point you somewhere better.
Web Development
Marketing sites, dashboards, and full web apps — written lean so they load fast and stay maintainable after handover.
- Hand-built, no page-builder bloat
- SEO and analytics set up properly
- Deployment and handover included
Android App Development
Offline-first Android apps like the ones we ship ourselves. Flutter or native Kotlin — chosen for the project, not the trend.
- Flutter and native Kotlin
- Offline-first architecture
- Play Store release handled
Who you'll work with
Haltansu is the studio of Saikat Halder.
B.Tech from IIT. Builder of BillKaro, Bloom, and the Developer Playground. When you hire Haltansu, the person you talk to is the person who designs, writes, and ships your software. No handoffs, no account managers, no surprises at delivery.
Have a project in mind?
Send a paragraph about what you're trying to build. We read everything and reply within two days — usually sooner.
Not ready to talk? Try the Playground