Kodex vs JavaScript Challenge

Kodex is an advanced code editor which brings powerful and desktop-class editor features to your iPad or iPhone: * Multi-caret editing, to quickly transform code selections. * Regex search and replace, with template matching and replace-all-matches. * Minimap which allows quick scroll navigation though the document. * Multiple window support * Syntax highlighting for over 150 languages. * Trackpad support with custom gestures to add cursors (ctrl+shift+click). * Auto complete feature (currently only for HTML). * Add as many guide columns as you wish (default 80 and 120 characters). * Configurable tab size (default 4 spaces), or insert spaces when pressing tab. * Draw hints for invisible characters such as new lines, tabs, and spaces. * Customizable key bindings, so you can configure Kodex to use the same key combos you are already used to. * Kodex smartly preserves your open documents so that your work stays as you left it between launches. * Light and Dark modes. Kodex is integrated with the Files app, so you can easily open files from any other app, and from your iCloud documents folder. You can launch Kodex QuickEdit from any file sharing view in any app to edit its contents without launching the main Kodex App (be aware this functionality depends on the host app implementing the sharing activity properly). Included are 10 editor themes, and several monospaced fonts for code editing (you can install your own preferred fonts using system profiles). Font size and line spacing are adjustable, so you can configure Kodex to best fit your preferred screen size, arrangement, and orientation. Kodex is not a compiler, and you can not build or run the code you edit from it. Think of Kodex as a NotePad++ or Sublime Text substitute for iPhone and iPad. Kodex is currently optimized for external keyboards, such as Apple's Smart Keyboard for the iPad Pro, or any bluetooth/USB keyboard. More virtual keyboard features will be added in a future version.

Feed your brain. Level up. Learn to write real JavaScript by solving one puzzle at a time, right on your phone. JavaScript Challenge is a single path of original coding problems, from your first function to graphs, dynamic programming and beyond. Every solution runs on-device in real JavaScript and is checked against hidden tests, so passing means it actually works. Free to start: the opening levels are free, then unlock the full path with a single one-time purchase. No subscription, no ads, no account. WRITE REAL CODE • A coder keyboard built for JavaScript: tab, brackets, quotes, snippets, undo • Instant feedback with named tests, expected vs actual output • Some levels enforce rules (no built-in array helpers, recursion required) so you learn the technique, not the shortcut LEARN THE RIGHT WAY • Three-tier hints from Rhino, your smug but surprisingly helpful mentor • Curated solutions after you solve: naive vs optimal, time and space complexity • Topics: strings, arrays, objects, closures, recursion, dynamic programming, sorting, searching, graphs, trees, hashing, bit tricks, grids, greedy strategies, intervals STAY MOTIVATED • One path, no shortcuts: easy → medium → hard, with performance tests on the hardest levels • XP, player levels, daily streaks and badges • Six themes, dark and light PRIVATE BY DESIGN • Works fully offline, no account, no tracking — your progress stays on your device • No ads, ever