Real-world Android apps, backend systems, and API design projects — built end-to-end from mobile to cloud.
The M-Pesa Analyzer Android app is a personal finance companion that reads M-Pesa transaction SMS messages directly from the device and organizes them into meaningful spending categories. Users get a clear breakdown of their inflows, outflows, send-money, buy-goods, and paybill transactions — all on-device without manual data entry.
The app leverages Retrofit to sync parsed transactions securely to the cloud backend, enabling richer analysis across devices. It features interactive charting via MPAndroidChart, PDF report generation with iTextG, and a bottom-navigation design built with Material 3 components for a clean and intuitive user experience.
The M-Pesa Analyzer web platform is the cloud backend and analytics dashboard that receives transaction data synced from the Android app. It provides a full-featured dashboard where users can visualize their spending habits, search through transaction history, set monthly budgets, and generate detailed reports.
Built on CodeIgniter 4 with MySQL, the backend exposes a secure REST API consumed by the mobile client. The web frontend lets users upload M-Pesa transaction statements (PDFs/CSVs) as an alternative input method, with the backend parsing and categorizing each entry automatically into a normalized database schema for querying and analysis.
The PC-to-Phone Copier Android app enables seamless, wireless file and text transfer between a desktop browser and an Android device. Authentication is performed by scanning a QR code displayed on the web interface, instantly and securely pairing the phone with the session — no cables required.
Beyond file transfer, the app integrates Google ML Kit's on-device text recognition (OCR) to extract readable text from photos or images captured on the phone. This means a user can photograph a printed document and have its text appear instantly in the web clipboard, bridging the gap between physical and digital content.
The PC-to-Phone Copier web platform acts as the relay hub between the desktop browser and the paired Android device. It hosts the web clipboard interface where users can paste or upload content on their PC, which the Android app then fetches from the backend in real-time.
The CodeIgniter 4 backend manages session-based QR code generation for device pairing, text and file storage, and API endpoints consumed by the mobile client. The web UI provides a clean interface for managing transferred files and text, with a history of all transfers within the active session.
The Device Data Collector Android app is the ingestion engine of the Device Intelligence System. It operates in the background to continuously harvest data from multiple device sources: SMS messages, call logs, contact lists, installed applications, GPS location history, and media files — then packages and transmits them securely to the cloud backend for analysis.
Built with a modular permissions model, the app requests only what is needed for each data type and uses Retrofit and OkHttp for reliable multi-part uploads. Firebase Cloud Messaging (FCM) enables the server to push collection triggers to the device, Lottie provides polished loading animations during sync, and Picasso handles local image preview rendering.
The Device Insights Dashboard is the analytical brain of the system. It ingests all data sent by the Android collector app — including SMS, call logs, contacts, installed apps, and GPS location trails — and processes them into rich dashboards that surface behavioral patterns, frequency trends, and cross-data correlations.
Each data category has a dedicated analysis module: the SMS module extracts communication patterns, the Calls module breaks down call frequency and duration, the Apps module profiles software usage, the Location module maps movement history, and the Correlation engine identifies hidden relationships across data types — all feeding into a unified insight report for each tracked client.
The Cloud Photo Gallery Android app is a sleek, modern photo management client built entirely with Jetpack Compose. It lets users browse their local device gallery and sync selected albums and images to their personal cloud storage, making photos accessible from any device.
The app uses Coil for performant, memory-efficient image loading and kotlinx.serialization for type-safe API communication. The reactive UI built with Compose Material 3 provides smooth grid browsing, full-screen viewing, and progress tracking for uploads and downloads — all backed by a RESTful CodeIgniter 4 backend.
The Cloud Photo Gallery web platform is the server-side backbone that stores, organizes, and serves photos uploaded from the mobile client. It provides a web interface to browse the hosted gallery, view albums, manage favorites, archive, or move items to trash — all protected with user authentication via CodeIgniter Shield.
The backend exposes a clean REST API with endpoints for CRUD operations on photos and albums, including soft-delete support using CodeIgniter's built-in model features. An explore view surfaces recent uploads, while separate views for Favorites, Archive, and Trash give users fine-grained control over their photo library from any browser.
Chege OS is a personal productivity and work-tracking platform designed to serve as a centralized operating system for managing ongoing projects, logging daily work done, recording milestones, and maintaining a structured timeline of deliverables. It eliminates the need for scattered notes and spreadsheets by consolidating all professional activity in one dashboard.
The platform supports structured logging — users can create projects, attach milestones, record daily progress entries, and review historical timelines. It is built on CodeIgniter 4 with a MySQL backend, features a responsive Bootstrap 5 admin interface, and integrates role-based access so multiple users or collaborators can track their own workflows independently.