KeiverHernandez

Senior React Native & TypeScript engineer

I build mobile and web applications that ship to worldwide audiences. 13+ years turning complex problems into performant, accessible interfaces across iOS, Android, tvOS, and web.

Currently focused on React Native cross-platform development and AI-assisted workflows.

Previously shipped products at Verizon, Pizza Hut, Catalis, Xevo, and Televisa.

Below are apps, tools, and experiments I've shipped, from Apple TV media clients to developer CLIs and cross-platform mobile apps. Available for contract and consulting work, get in touch.


TypeScript, React Native, iOS, Android, tvOS, UX, Next.js, Expo, WCAG
Featured

Projects

Tomo TV - Jellyfin Media Client

jellyfin, apple-tv, media-server, tvos, streaming, transcoding

Stream videos from your Jellyfin server to Apple TV with automatic codec transcoding. H.264 and HEVC play natively; other formats transcode on-the-fly. Built with expo-tvos-search for native search integration. Includes folder browsing, subtitles, iCloud Keychain sync, and native tvOS search.

image-tiler-mcp-server - Vision-Optimized Image Tiling MCP Server

mcp, vision, image-tiling, claude, openai, gemini

MCP server that splits large images into optimally-sized tiles for LLM vision models. Prevents automatic downscaling by Claude, GPT-4o, and Gemini.

expo-tvos-search - Native tvOS Search for Expo Apps

tvos, react-native-tvos, expo, swiftui, search, apple-tv

Native tvOS search integration for React Native Expo apps via .searchable Swift modifier. Easily add Spotlight-style search functionality to your Apple TV apps built with Expo.

tvos-assets - tvOS Asset Bundle Generator

tvos, xcassets, cli, sharp, apple-tv, xcode

CLI tool that generates complete tvOS Images.xcassets bundles from an icon and background image. Produces 39 files including parallax app icons, Top Shelf images, and splash screen assets.

Generative Poster Maker

generative-art, svg, poster, design, procedural, social-preview

Create unique procedural posters with 50+ color palettes and 19 artistic styles. Free online tool to generate and download custom SVG, PNG, or JPG images for social media, blogs, and more.

Image Metadata Remover

privacy, exif, gps, metadata, photos, images, webp

Remove EXIF data, GPS location, camera info, and timestamps from photos. 100% client-side processing - your images never leave your device. Free, private, no upload required.

Lazy Webp - Batch Image to WebP Converter

webp, image-converter, cli, macos, sharp, batch

CLI tool and native macOS app to batch convert images to WebP format. Drag-and-drop or command-line with concurrent processing, atomic writes, and mtime-based skip logic.

Unicode Blocks Explorer, Search Emojis by Name

unicode, javascript, emoji, utf-8, kana

Search specific unicode characters by name or description. Use an easy slider to scrub through the unicode blocks and bookmark favorites

Experiments

Lab

Cubita - Forest Runner Arcade Game

game, arcade, runner, ios, android

Swipe or tap your way through a vibrant forest, dodging trees and wildlife while the pace keeps picking up. How far can you run?

Moji Grid - Japanese Kana Wallpaper Creator

japanese, hiragana, katakana, ios, android

Create beautiful, customizable Japanese character grids for learning and teaching. Arrange hiragana, katakana, and kanji with complete style control and easy export capabilities.

Symbol Mind - Egyptian Hieroglyphs Memory Game

memory, game, egyptian, hieroglyphs, puzzle

Challenge your memory with this engaging puzzle game featuring authentic Egyptian hieroglyphs. Progressive difficulty levels and special cards make each game unique!

Facel - Face Detection and Tagging App

ai, face-detection, photo-tagging, ios, android

Tag and label faces in your photos privately and securely. No cloud processing, no data collection - just simple, effective photo organization.

Bidirectional Apple Watch ↔ React Native

watchOS, React Native, Expo, TurboModule, WatchKit

Learn how to implement bidirectional communication between React Native and Apple Watch using TurboModules, WatchConnectivity framework, and TypeScript. Complete guide with code examples for iOS and watchOS integration.

Barlog - Barbell Plate Calculator App

react-native, typescript, ios, android, fitness

Barlog, barbell minimum plates calculator, iOS app, Android app, with Figma design, React Native code, and SVG images.

Apple Vision vs YOLOv11n

iOS, ML, Vision, YOLO, Swift

A comparison of Apple Vision and YOLOv11n for face detection in iOS apps, including performance, memory usage, and accuracy.

Barlog UX Case Study

design, ux, ui, experiment, accessibility

Experimenting with a full-screen slider for weight adjustments in a virtual barbell, exploring on UX and accessibility

Archive

+2 projects

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