Sirkasir

Overview

Sirkasir is a fully offline point-of-sale (POS) application built for small business owners who need a simple, secure, and reliable way to record sales without relying on network connectivity. I created this app for my sister as a more secure and intuitive replacement for her existing POS system, which suffered from poor usability and vulnerability to employee manipulation.

Problem

My sister’s previous POS solution presented two major issues:

• The interface was not intuitive, making it slow and inefficient for daily use.
• Employees could easily manipulate data, since the app offered no permission control or owner-level access.

She needed a POS system that would work anytime (even without internet), provide proper access control, and remain simple to operate.

Solution

I built Sirkasir as a 100% offline POS system with a clear separation between owner mode and employee mode.
A secure PIN is required to access owner functionalities such as editing items, viewing analytics, and inspecting sales history.

To support daily retail operations, the app includes Bluetooth thermal printer support, allowing instant receipt printing directly from the device.

I also integrated Firebase Analytics, Crashlytics, and Remote Config to monitor app behavior, track issues, and remotely control feature flags or configuration for future updates.

Key Features

• Fully Offline POS System (no internet required)
• Owner–Employee Mode with PIN authorization
• Bluetooth Thermal Printer support
• Sales Tracking & Basic Analytics
• Firebase Integration:
  • Analytics
  • Crashlytics
  • Remote Config for future update handling
• UI designed specifically for real retail workflow

Tech Stack

• Flutter (mobile development)
• Bluetooth Thermal Printer (purchased for testing and development)
• Firebase Analytics, Crashlytics, Remote Config
• Figma (UI/UX design)

My Role

I served as both developer and designer, handling everything from UI/UX design in Figma to implementing the app, Bluetooth printing, offline logic, and Firebase instrumentation.

Challenges & Learnings

This project taught me several key lessons:

• It was my first time releasing an app to the Google Play Store, requiring significant trial and error.
• Building reliable Bluetooth thermal printing involved deep testing and handling various connection issues.
• Ensuring the app worked fully offline required careful planning for data storage and user flows.
• Integrating Firebase taught me how to track user behavior, diagnose crashes, and prepare for future updates using Remote Config.
• The app did not gain users, which helped me understand that building a sustainable app business requires more than development — marketing and distribution matter just as much.
• The app was eventually removed from the Play Store because another account under the same identity was terminated, which affected this app’s publishing account as well.

Links

• Removed from Google Play (no longer available)