A fully custom BottomDrawerLayout that supports drag-to-expand/collapse, nested scrolling coordination, and a configurable handle view. It uses custom OnDragListener and ScrollCompat to delegate drag events and handle overscroll physics. The widget is self-contained, relies only on standard Android View classes, and can be extracted for use in any Android app needing a bottom sheet with customizable behavior.

A TTS manager that wraps the Android TextToSpeech engine and integrates with a notification (TtsNotification) for playback controls. It provides play, pause, resume, skip, and stop functionality, supports streaming text via Kotlin coroutines (Playable), and handles lifecycle with context bindings. The component is decoupled from app-specific logic and can be reused to add TTS capabilities to any Android app.

A singleton disk cache built on DiskLruCache that stores JSON-serializable objects with MD5-based keys. It supports put, get, remove, and clear operations, configurable cache size and directory, and uses callback listeners for async access. The class is generic and could be extracted to cache any serializable data in any Android or Java project, demonstrating a clean abstraction over DiskLruCache.

Manages a pool of reusable WebView instances (ResuableWebView) to avoid memory leaks and reduce WebView creation overhead. Provides obtain() (with optional URL) and recycle() methods, handles WebView destruction, cookie syncing, and scroll position restoration. The pattern is applicable across Android apps that need to embed multiple WebViews efficiently and can be extracted with minimal changes.

A utility class that uses reflection to detect notch screens across multiple OEMs (Huawei, Xiaomi, OPPO, Vivo, etc.) by reading internal system resource IDs. It provides methods to check if a device has a notch and to get the notch height. This solves a recurring Android UI problem and can be reused directly in any app needing safe display area calculations.