A Chrome extension that teaches you Japanese out of the pages you were going to read anyway. Words you are ready for get swapped into the English around them. Nothing asks for your evening.
Free. Chrome, Edge, Brave, Arc and other Chromium browsers, version 114 or newer.
Every spaced repetition app has the same problem. Reviews are a chore you schedule, so the app competes with the rest of your life, and it loses.
This one has no reviews. It reads what you do with a word sitting in a page you already chose to read. Hold one until the glow fills and you have said you read it. Click it and you have said you could not. Neither costs you anything.
Reading research puts unaided comprehension at about 98% of the words being ones you know. So the words you cannot read yet are capped at two in a hundred, and the words you can read are not capped at all. The hard share stays where it is for years. The Japanese share grows behind it.
Furigana is no use if you cannot read kana. So each sound is spelled in kana
once you can read it, and in letters until then: neko, then
ねko, then ねこ, then nothing.
Substitution is a dictionary lookup and it happens in your browser. Two things are optional, off by default, and use your own API key: asking a model about a word, and translating a whole sentence with DeepL.
Optional. Everything works without one. An account copies your progress to your other browsers, and nothing else. You can delete it, and everything in it, from the extension's own settings.