Released 2026-01-08 · Store name “英語N+1” · v1.3.2 · 42 MB · free · offline after setup
English N+1 is an offline AI English tutor that dynamically generates content just slightly above your CEFR level. That is what the N+1 in the name means: a little beyond where you are now, and no more.
Why it was made#
My English peaked on the day of the university entrance exam and has been slipping ever since. Every so often I want to brush it up, but the market is mostly beginner material, and everything else is either too easy or too hard, so it is hard to find anything that matches your actual level.
The trigger was a period when AI clearly understood English far better than other languages. I tried to talk to AI in English as much as possible during that time, but I still had to look up words constantly, so I wanted to study. Since the right material could not be found, the app generates it to fit.
Who it is for#
People who want to talk to AI in English. People who already have basic English but do not know how to move up from there.
How it was done, and where it got stuck#
The approach was to collect open-source graded English material, define a large vocabulary per level, and map each word’s meaning between a harder and a simpler version. Generation follows that mapping to control difficulty, so the content lands at N+1.
Technically it reflects a learning philosophy, and it still needs someone with real English-teaching expertise to refine it. Most of the time went into organising the open-source data and material, and a fair amount into the pipeline and prompts that generate the lesson texts.
Where it stands#
What can be improved is mainly the material, but that needs either licensed content or teachers with real classroom experience. It is only worth investing in the other features once the material is good enough. If you have the resources or the skills, I would welcome the help.