EinkBro is a full-featured Android WebView-based browser specifically optimized for e-ink displays. It provides a rich reading experience with features like ad blocking (via a native C++ engine forked from Brave), paragraph-level translation (Google/DeepL/OpenAI/Gemini), text-to-speech (Edge TTS, system TTS, Web Speech polyfill), reader mode, EPUB reading, user script support, and AI agent capabilities (chat-with-web, multi-step browsing tasks). The architecture is a monolith Android app with three Gradle modules (app, ad-filter, adblock-client) using Kotlin, Jetpack Compose, Koin DI, Room database, and OkHttp. Key entry points include BrowserActivity (main browser), EBWebView (custom WebView wrapper), and various delegate classes for tab management, translation, AI chat, and gesture handling. The codebase demonstrates strong engineering practices with extensive unit tests, a well-structured delegate pattern, and several reusable components such as type-safe SharedPreferences delegates, a standalone PDF parser, and a jsdom-based test harness for WebView-injected JavaScript.
KOReader is a document viewer application primarily designed for e-ink readers, supporting a wide range of formats including PDF, EPUB, DjVu, CBZ, and more. It provides a full-featured reading experience with file management, annotation, dictionary lookup, OPDS catalog browsing, Calibre integration, cloud storage, and extensive customization through a plugin system. The architecture is a monolithic Lua application built on a custom widget toolkit with an event-driven UI manager, platform-specific device abstraction layers (Kindle, Kobo, PocketBook, reMarkable, Android, SDL), and a robust caching and rendering pipeline. Key entry points are `reader.lua` for the main application and `kodev` for development/testing. The codebase is large and mature, with a strong emphasis on performance and e-ink optimization, but shows some technical drift in the form of deprecated code paths, platform-specific hacks, and a fragmented keyboard layout system.
ESPHome Designer is a Home Assistant custom component that provides a visual drag-and-drop editor for designing display layouts on ESP32/ESP8266 devices running ESPHome. It supports multiple rendering protocols including native ESPHome C++ lambdas, LVGL, OpenEPaperLink (OEPL), and OpenDisplay (ODP). The editor features a canvas with zoom/pan, snap-to-grid, drag-and-drop, lasso selection, and a property panel for configuring widget attributes. Widgets are organized as plugins, each providing render, export, and lifecycle hooks for all supported output formats. The system can generate complete ESPHome YAML configurations including hardware definitions, sensor registrations, font loading, and display lambdas. The architecture is split between a Python backend (Home Assistant integration) and a JavaScript frontend (Vite-built SPA). The backend provides REST APIs for layout CRUD, entity history proxying, image/RSS proxying, hardware profile management, and PNG rendering. The frontend manages state via an AppState singleton with undo/redo, communicates with the backend through a bridge, and supports offline YAML parsing. An AI integration allows generating layouts from natural language prompts using multiple providers (Gemini, OpenAI, OpenRouter). The codebase demonstrates strong engineering practices with a plugin-based architecture, adapter pattern for multi-format export, schema-driven property panels, and extensive test coverage (200+ Vitest tests plus Python tests). It is actively maintained with CI/CD pipelines, quality gates, and regular releases. While the widget plugin surface is large and some legacy modules coexist with newer code, the overall design is modular and extensible.
HomePlate is embedded firmware for Soldered Inkplate e-paper displays, turning them into wall-mountable smart dashboards. It connects via WiFi to Home Assistant (through MQTT and screenshots) or TRMNL to display content such as Home Assistant dashboards, TRMNL screens, custom images, QR codes, and text messages. The firmware is built on PlatformIO with FreeRTOS, supporting deep sleep for battery life, OTA updates, and a captive portal web configurator. It uses MQTT for Home Assistant discovery, exposing sensors (WiFi RSSI, battery, temperature) and config entities. The architecture is activity-driven: an activity queue dispatches display modes (HomeAssistant, Trmnl, Info, etc.) triggered by MQTT, timers, or physical buttons. Power management is a core focus, with configurable sleep schedules, a wakelock system for critical operations, and always-on mode. The codebase is well-organized, includes unit tests, and has reusable components like a buffer stream wrapper and sleep scheduling logic. It is actively maintained with CI/CD, releases, and a web installer.