Easy on your data plan
Some run entirely on-device; the ones that go online cache what they fetch, so nothing is re-downloaded and a dropped signal isn’t a dead end.
Apps I build for fun — and ship.
I’m Mahmudunnobi Rain, a software engineer by trade. BuildByRain is the side of my work I do purely for the fun of it — small apps I design, build, and ship end to end — from Google Play to the App Store.
Common threads
What they share
Different problems, but the same instincts run through all of them.
Work
Projects
Personal projects — shipped and live, from Google Play to the App Store: reading, business, utilities, fitness, games, and a living desktop.
App Live
Pathok – জনপ্রিয় বাংলা বই
Bengali ebook reader with free books from Bangladesh, India, and translated world literature.
- Flutter
- GetX
- FastAPI
- SQLite cache
App Live
Medic | BD Prescription & Drug
Mobile prescribing workspace for doctors in Bangladesh — write, manage, and share prescriptions with drug lookup.
- Flutter
- GetX
- SQLite
- Cached drug lookup
App Live
MiniPOS – Shop Khata & Dues
Easy sales, purchase & due tracker for small shops. Works offline.
- Flutter
- Drift / SQLite
- Google Drive backup
- Bangla + English
App Live
ScanHub – PDF Document Scanner
Scan documents to PDF — fast, private, and fully offline. No account, no cloud, no ads.
- Flutter
- GetX
- ML Kit (on-device)
- On-device OCR
App Live
গল্পঘর Golpoghor – Bangla Golpo
Bangla serial fiction — new writers publish love, horror, mystery, and sci-fi stories part by part, alongside classic novels, free to read.
- Flutter
- GetX
- FastAPI
- Firebase
App Live
Vividwall – Live Video Wallpapers
Live video wallpapers for your Mac — stunning NASA scenes and sci-fi interfaces built in, or bring your own. Private and battery-smart.
- Swift
- SwiftUI
- AVFoundation
- Sandboxed
App Live
HomeFit Plan: Home Workouts
A four-week home workout plan built around your goal, equipment, and the days you can train — then it helps you stick to it.
- Swift
- SwiftUI
- CloudKit sync
- Offline-first
App Coming soon
Calculator+ — Calculator Vault
A private, encrypted vault disguised as a working calculator — hide photos, videos, files, and notes behind your PIN.
- Swift
- SwiftUI
- AES-256-GCM
- Face ID
Game Live
Ludo Pagla
Classic Ludo you can play offline — free-for-all, Team Up 2v2, and bots, with the house rules you actually play by.
- Flutter
- Pure Dart engine
- Offline play
- Bangla + English
The lab
A lab for serious software.
BuildByRain is my workshop for the apps I want to exist — each one a personal project, built with real care and shipped to anyone who wants it. My professional and client work is separate, and isn’t part of this portfolio.