Kohai (“the app”, on Android and in the browser) is made by Low & Slow Studio (“we”). This policy explains what the app collects, why, who else sees it, and how to delete it. Short version: we collect what the app needs to work, we don’t sell anything, and there are no ads or analytics services.
What we collect
Your account. A display name, your email address, and a password. We store a scrambled form of your password (a salted hash), never the password itself. At sign-up we ask whether you’re an adult, and if not, your birth year, so we can apply the protections for younger learners described below. You confirm your email address before you can sign in.
Your study work. Practice-test answers and scores, flashcard answers, notes, and your study log. This is what lets the app show your progress and decide what to review next.
Recordings for the course. If you’re a reviewer, recordings you make of listening lines are stored so they can be approved into the course.
Talk (voice messages). If you use Talk, your voice recordings go to our server so your teacher or learner can hear them. Our own server turns them into text so they can be read as well as heard. Your audio is never sent to an outside transcription service.
Notifications. If you allow notifications, your phone gives the app a push token, which we store so we can tell you about new Talk messages.
Reports you choose to send. A problem report is sent only when you write one and tap Send. If the Android app crashes, it asks you once whether to send crash reports and remembers your answer; only if you agree are they sent to us. A crash report holds the technical trace of where the app failed, the app version, your phone model and the Android version.
Diagnostics, to fix problems. The apps tell our server which screens you opened, which requests failed (with the server’s reference code for the failure) and when something like a sound wouldn’t play. The server keeps a log of each change you make (when, which account, what it saved), and of requests that failed or were slow. It never records passwords, sign-in or email links, your email address, what you look up or write for yourself, or Talk recordings and transcripts. Only our admins can read it, and it’s kept for 400 days (daily totals after that).
Backups you ask for. You can download a backup (flashcards, tests, study log and notes) and a spreadsheet of your words, and restore a backup into any account. Those files go where you put them. Talk conversations aren’t included, because each one belongs to two people.
What stays on your phone
The app keeps your sign-in, settings, tests in progress and flashcard answers that haven’t been sent yet on your phone. Temporary audio files are kept in the app’s cache. The home-screen widgets keep today’s cards and practice on the phone. The app also keeps a small rolling log of what it did and what failed (two files of at most 256 KB each); it’s never sent by itself, and you can share it as a file from Account → Share app log, for example when asking for help. The app turns off Android’s automatic cloud backup.
Permissions
| Permission | Why |
|---|---|
| Internet | To reach our server. |
| Microphone | Only while you record something yourself: a Talk message, a teacher greeting, or a reviewer recording. The app never listens in the background. |
| Notifications | To tell you about new Talk messages. Optional. |
Who else sees your data
We don’t sell or rent your data, and we don’t share it for advertising. The app has no ads, no analytics services, and no third-party crash reporting: diagnostics and crash reports go only to our own server. A few services are involved in running it:
- Our server. Your account and study data are stored on a server operated by Low & Slow Studio in the United States.
- Cloudflare carries traffic between the app and our server, as our network provider.
- Google Firebase Cloud Messaging delivers notifications. A notification carries only the sender’s display name and an unread count, not the message.
- Google Play tells the app when an update is available.
- Email (sign-up confirmation and similar) is sent from our own mail relay.
The app also opens some links in your browser, such as the Japan Times or a Google search. Those sites have their own privacy policies.
Teachers and learners
Teachers are approved by us before they can take part. A teacher hears and reads the Talk messages you exchange with them.
Children
Children under 13 can’t sign up on their own: a parent or guardian creates the account. Learners under 18 can’t be found or contacted by strangers in the app.
Security
All traffic between the app and our server is encrypted (HTTPS). Passwords and sign-in tokens are stored only as hashes. Our server is backed up so your work isn’t lost if hardware fails.
Keeping and deleting your data
We keep your data while you have an account. You can delete your account yourself at any time, in the app or on the web: see Delete your data. Deletion is immediate and removes your account, test history, flashcards, notes, study log, and everything you recorded. In Talk, the other person keeps their own messages; yours show as from a deleted account, with no audio. Problem reports you already sent are kept so they can be looked into, and the diagnostics log keeps its entries until they age out after 400 days. Recordings a reviewer made that were already approved into the course stay in the course unless you ask us to remove them too.
Changes
If this policy changes, we’ll update the date at the top. If a change affects how your data is used, we’ll tell you in the app first.
Contact
Questions or requests: [email protected].