when vs Krumbit

"四次元年表" is a project where users collaborate to build a database that encompasses all historical events, from the origins of the universe to the endless "now", regardless of the field. It aims to accurately display both temporal and spatial distances by making "where" as important as "when".

Learn something useful every time you scroll. Krumbit is a microlearning app that turns short-form scrolling into short-form learning. Watch quick video lessons on science, health, history, and everyday facts, then take a fast quiz to lock in what you just learned. Built for people who love the pace of short videos but want something smarter, Krumbit helps you build a better habit without giving up the format you already enjoy. Whether you are on your commute, taking a quick break, or winding down at night, you can make real progress in minutes. What you can do in Krumbit: Watch bite-sized video lessons Take quick quizzes after each lesson Build a daily streak and track your progress Explore science, health, history, and everyday facts Send feedback directly in the app and help shape the product Krumbit makes scrolling feel productive: fast, visual, and actually useful. Download Krumbit and turn your scrolling habit into a learning habit.