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Made in India · Android

Offline GST calculator and invoice app for India: PocketGST, built by QalbIT.

GST maths and invoices, 100% offline. PocketGST is an offline GST calculator and invoice app for Indian shops, freelancers and traders: instant CGST/SGST splits and professional GST invoices with no signup and no internet. We designed, built and ship it.

Build something like this →Visit pocketgst.com ↗ (opens in a new tab)

At a counter with no signal, an app that needs the cloud is not a product. Offline was the requirement, not a feature.

PocketGST · mobile GST invoicing

  • 700+

    Play Store downloads

  • 4.6★

    Average rating

  • 12

    Indian languages

  • 100%

    Offline core

Trusted by companies worldwide

  • Bloomford
  • Contractor Plus, Inc.
  • Snappy Stats
  • Ad Lunam
  • Local Buzz
  • CyberFind
  • Hellory
  • 5.0Clutch · 8 client reviews
  • 4.9Google · 18 reviews
  • Top ratedUpwork · 100+ reviews · 5K+ hours worked
  • TopTracker7K+ hours tracked with clients

The opportunity

GST is daily maths for millions of small businesses.

Kirana shops, freelancers and traders across India do GST calculations and invoices every day, but most tools demand a signup, a subscription and a steady internet connection. PocketGST makes the maths and the invoice instant, offline and free to start.

  • Connectivity is not a given

    A counter in a market street cannot wait for a cloud round trip to print a bill.

  • Signups kill adoption

    Asking a shopkeeper to create an account before their first invoice loses most of them.

  • Compliance errors are expensive

    Manual CGST/SGST splits and missing HSN codes turn into filing problems months later.

What we built

From calculation to invoice in 30 seconds.

Three capabilities that work with the phone in aeroplane mode: correct GST maths, a professional invoice, and nothing leaving the device. The same engineering shows up in our case studies.

GST calculator

Instant CGST / SGST split as you type.

Enter an amount, pick a GST rate, and PocketGST splits CGST and SGST instantly for intra-state supplies: no formulas, no errors, updated live as you type.

  • Live CGST / SGST / IGST split
  • All standard GST slabs
  • Works fully offline
PocketGST calculator · CGST and SGST split as you type
PocketGST invoicing · a GST invoice shared from the phone

Invoicing

Professional GST invoices, shared on WhatsApp.

Generate clean, GST-ready invoices with HSN codes on line items and professional PDF templates, then share a PDF straight to WhatsApp, no cloud lock-in.

  • Multi-item bills with HSN
  • Professional PDF templates
  • One-tap WhatsApp sharing

Offline & private

No signup, no cloud, no internet needed.

Everything runs on device, DPDP-aligned and privacy-first, in 12 Indian languages, so billing at the counter never waits on a network or an account.

  • 100% offline, on-device data
  • DPDP-aligned, no cloud upload
  • 12 languages including Hindi and Tamil
PocketGST offline · the app working with no connection

Who it is for

Built for Indian shops, freelancers and traders.

Not an accounting suite. A fast, private tool for the person actually handing over the bill.

  • Retail & kirana

    Fast billing at the counter with CGST/SGST split and WhatsApp PDF sharing.

  • Services & freelancers

    Quotes, GST invoices and professional templates without cloud lock-in.

  • Wholesale & trade

    Multi-item bills, HSN on lines, and GSTR helpers when filing season hits.

How it works

Three steps to GST.

No onboarding, no account, no tutorial. Install and bill.

  1. Download

    Get PocketGST from the Play Store and open it, no account, no permissions drama.

  2. Calculate

    Enter an amount, pick a GST rate. Instant CGST/SGST split for intra-state supplies.

  3. Save & share

    Turn it into a GST invoice and share the PDF on WhatsApp in seconds.

Under the hood

Offline-first, privacy-first, built for Bharat.

PocketGST is engineered to work with zero connectivity: the GST logic, invoicing and storage all run on device, so it stays fast and private even at a counter with no signal, in the user’s own language.

  • Offline-first Android app

    GST calculation, invoicing and storage all run on device: the core works with no internet at all.

  • Privacy by design

    DPDP-aligned with no cloud upload and no signup: data stays on the user’s phone.

  • Built-in GST rules

    Standard slabs and CGST/SGST/IGST logic encoded so users get correct maths without formulas.

  • Multilingual UX

    12 Indian languages including Hindi and Tamil, for real accessibility across the country.

  • Invoicing & sharing

    Professional PDF templates with HSN on line items and one-tap WhatsApp sharing.

  • Freemium model

    15 free invoices a month with a Pro tier from ₹999/year, accessible to the smallest business.

  • Android
  • Offline-first
  • On-device storage
  • GST rules engine
  • PDF invoicing
  • 12 languages
  • DPDP-aligned
  • Play Store

What it proves

Consumer mobile, under the hardest constraints.

Regulated calculation logic, offline data and document generation on a phone, shipped to the Play Store and maintained, not prototyped.

What shipped

  • GST calculator with live CGST/SGST/IGST split
  • Multi-item invoices with HSN codes on line items
  • Professional PDF templates and one-tap WhatsApp sharing
  • 100% offline, on-device storage with no cloud upload
  • 12 Indian languages including Hindi and Tamil
  • Freemium model with 15 free invoices a month

  • Live on the Play Store

    700+ downloads at a 4.6★ average rating, maintained as a real product rather than a portfolio piece.

  • Compliance logic we own

    GST slabs and split rules encoded and kept current: the kind of domain logic clients cannot afford to get wrong.

  • Proof of mobile range

    Offline-first architecture, on-device storage and document generation in one shipped Android app.

Our clients · reviews

Teams who trusted QalbIT

Short feedback from clients and products we work on across web, mobile, SaaS and internal tools.

  • Testimonials from long-term custom software development and SaaS product clients.
  • Covers ERP systems, B2B marketplaces, booking platforms, and web & mobile app development projects.
  • Real text and video reviews from founders, CTOs, and product teams who partnered with QalbIT for delivery.

  • Video review

    Rated 5 out of 5.
    “Working with QalbIT was an absolute pleasure. They understood our brand vision, delivered a WordPress site that is easy to navigate, and kept communication smooth throughout. I would absolutely recommend them to anybody.”
    Imdad Ali KadiwalaFounder, Netzur

  • Written review

    Rated 5 out of 5.
    “QalbIT is a fantastic dev partner. They provide quality work, good communication and go above and beyond. Fantastic work delivered by QalbIT and his team. Can’t give enough credits with regards to how they work and at which speed they do it. Top team.”
    Joost HesselberthFounder of Ad Lunam Investments PTY LTD

  • Written review

    Rated 5 out of 5.
    “I would recommend QalbIT to everybody. QalbIT has been developing all my front-end & backend systems complete to my requirements. They have excellent technical knowledge and listen very well to the needs of their customers. And above all, they are great people.”
    Wouter SantensExecutive Search Consultant at Bloomford

  • Written review

    Rated 5 out of 5.
    “They listened to my ideas and came up with a plan for development then executed that plan to completion. I liked their attention to detail and communication skills. Very responsive.”
    Osmond MwanyikyCTO, Bocsit

  • Written review

    Rated 5 out of 5.
    “QalbIT quickly integrated four platforms quickly. Square, Stripe, PayPal, and Coinbase were all successfully used. The vendor provided an active communication process, maintaining timely deadlines despite the research-heavy service. They also offered post-launch support.”
    Roshan SethiaCTO, Contractor Plus, Inc.
View all testimonials

More products

Software products we designed, built and still run.

Four products, four domains, one team. Every agency claims it can take an idea to production. These are ours, in the open, with the architecture decisions and the operating record attached.

Build yours

Want a mobile product like PocketGST?

We designed, built and ship PocketGST ourselves, offline-first, multilingual and privacy-first. That is the same mobile and product engineering we bring to client work. Tell us what you want to launch.

  • Offline-first architectureApps that keep working with no signal, then sync cleanly when there is one.
  • Regulated domain logicTax, pricing and compliance rules encoded and tested, not left to the user.
  • Shipped to the storesRelease process, review, updates and support: we have done it end to end.

Get your free estimate

Three quick questions: scope, approach and a price range back within 48 hours. No sales call required first.

What do you need built?
When do you want to start?
Where should we send the estimate?

Answer all three questions above, then send.

NDA-friendly · IP yours from day one

FAQs · PocketGST

Frequently asked questions about PocketGST

Using the app, what it costs, and having us build a mobile product like it for you.

Talk to our product team →
Yes. The GST calculator, invoicing and storage all run on device. You can install it, bill a customer and share a PDF with the phone in aeroplane mode.
No signup at all. The app opens straight into the calculator, and no data is uploaded to a cloud.
Free to start with 15 invoices a month. The Pro tier begins at ₹999 a year for unlimited invoicing and the full template set.
12 Indian languages including Hindi and Tamil, so the app is usable in the language the counter actually works in.
It is DPDP-aligned by design: there is no cloud upload, so business and customer data never leaves the user’s phone.
Yes. Offline-first architecture, regulated domain logic and store releases are all things we have shipped. You get a written scope and price range within 24 to 48 hours.
Yes, completely. The GST calculator, invoicing and PDF generation run on the device, so it works at a counter with no signal. Nothing is uploaded to a cloud, and no signup is needed.
All standard GST slabs with the CGST, SGST and IGST split as you type, multi-item bills with HSN codes, and professional PDF invoice templates you can share on WhatsApp in one tap.

Next step

Have a mobile product in mind?

Send it in two lines. We will tell you what we would build first, what it costs and what we would leave out, before you spend anything.

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