Try Checkpoint in your browser.
This is the early version of the web app. It is free. There is no install and no credit card. It opens in any modern browser on Mac, Windows, Linux, iPad, or Android.
How to start (first time)
Follow these on whatever device you are reading this on. Most of it is stuff you already do every day — nothing weird.
- 1
Tap the button above to open the app.
It opens app.checkpoint.study in a new tab. If your browser asks “is this site safe?” — yes, it is mine. - 2
Create an account.
Use email + password, Google, or Apple. Whichever is fastest. You can use the same login on the iPhone app later if you want. No credit card, no payment screen — that is on purpose. - 3
Pick a goal and a starting level.
Checkpoint will ask a couple of questions: which language (Japanese is up today), where you are starting from, how much time you want to spend. Pick anything — you can change it later. The whole step takes a minute. - 4
Do one short session.
On the home screen, tap the first lesson or the day’s review. The first session is meant to feel weird until it suddenly does not. Do not worry about getting it “right” — the algorithm needs to see you miss a few before it knows what to teach you. - 5
Bookmark the page so you can find it tomorrow.
⌘ + D on Mac or Ctrl + D on Windows. On Chrome / Edge / Safari you can also click the little Install icon in the address bar to add Checkpoint to your home screen like a real app — same link, no extra account.
Tell me what is broken. Tell me what is missing.
Checkpoint is a small one-person operation. There are no QA testers, no support team, and no way for me to know what is wrong on your screen unless you tell me. Every bug report and every “this is confusing” note from you genuinely changes what I build next week.
You are not bothering me. You are the reason the app gets good. If something feels weird, broken, slow, ugly, or just wrong — please say so. There are no stupid reports.
How to send feedback
Pick whichever is easiest. They all reach me.
hello@checkpoint.study
A one-sentence email is enough. “The streak counter froze when I hit 12” or “this kanji card is upside-down” — perfect bug report.
Take a screenshot and attach it.
On Mac: ⌘ + Shift + 4 to crop. On Windows: Win + Shift + S. Drag the screenshot into the email. A picture of the weird thing usually tells me more than a paragraph would.
Tap the feedback bubble in the bottom-right.
Look for a small message icon at the bottom-right of any screen. Tap it, type whatever is on your mind, send. It goes to the same inbox as the email above.
What is worth reporting?
Anything. Truly. To make it easier, here are some things I genuinely want to hear:
- Bugs. Anything that crashes, freezes, shows the wrong thing, or just looks broken.
- Confusing moments. If you ever thought “wait, what do I do here?” — that is a bug in the design, and I want to know.
- Wrong Japanese. If a translation or sentence looks off, please flag it. I would rather fix one now than ship it to everyone later.
- Feature requests. “I wish it could…” is one of the most useful sentences you can send.
- What you liked. Knowing which moments felt good helps me know what to do more of.
A couple of small notes
- · This is a beta. You will see rough edges. That is the point.
- · Your progress saves automatically. Refreshing the page is safe. Closing the tab is safe. Sleep your laptop — also safe.
- · The same account works on the iPhone app when you switch. No need to re-create anything.
- · There is no charge to test. There will never be a charge to test.