Amethyst vs Readwise Reader

Amethyst is a free, open-source tiling window manager for macOS inspired by xmonad. It automatically arranges application windows into non-overlapping layouts using keyboard shortcuts, without requiring System Integrity Protection to be disabled. Amethyst supports multiple layout algorithms including tall, wide, fullscreen, and column layouts.

Readwise Reader is Read-later app with highlighting, annotations, and integration with Readwise's spaced repetition system.. It is available under a paid model. This tool falls under the productivity category.