Privacy Policy

This policy covers every Android application published by onLLM. It applies to all of the apps listed below, in their current and future versions, unless an app's own store listing points to a different policy.

Effective date: 29 September 2026. Last updated: 29 September 2026.
Developer: onLLM · Website: onllm.dev · Contact: contact@onllm.dev

Summary

Apps covered by this policy

This policy covers every app we publish. If we release another one, it is added here, with its exact permissions and behaviour, before it goes on the store, and the effective date above changes.

Information we collect

We collect no personal information whatsoever. We do not ask you to create an account, we do not ask for your name or email address, and we have no server that could receive your data. Specifically, we do not collect:

• Names, email addresses, phone numbers or any other contact details
• Location data of any kind, precise or approximate
• Device identifiers, advertising IDs or installed-app lists
• Usage analytics, session recordings, screen views or event logs
• Crash reports or diagnostic data, unless you yourself choose to send one from your own email app (Yappo only, see below)
• Photos, videos, audio recordings, contacts, calendar entries or files, unless you yourself choose to attach a recording to a message you send us from your own email app (Yappo only, see below)

What happens on your device

Our apps read sensors and store your preferences locally in order to work. This information stays on your phone, in the app's private storage, which other apps cannot read. It is never transmitted to us or to anyone else.

Sensor readings

Apps read the sensors their function requires — for example the accelerometer and gravity sensor in Level. These readings are processed in memory, moment to moment, purely to draw what you see on screen. They are not written to storage and not sent anywhere.

Microphone — Sound Meter only

Sound Meter needs the microphone permission because measuring loudness is its entire purpose. We want to be precise about what that does and does not mean:

• The microphone is opened only while the meter screen is open and in front of you. It is released as soon as you leave the screen or the app.
• Audio is analysed in memory to compute a decibel figure and a frequency spectrum. The audio itself is never recorded, never written to storage and never transmitted. There is no audio file to leak, and the app has no internet permission with which to send one.
• A “recorded session”, if you start one, stores decibel numbers only — one loudness value per second, plus the session's duration, average, peak and time above 85 dB. It contains no audio and no speech.
• Sessions are stored in the app's private storage on your phone. They leave the device only if you tap Share and choose where to send the CSV file, at which point the receiving app's own privacy policy applies.
• The home screen widget and the quick settings tile display the last reading the app itself took. Neither ever activates the microphone on its own.

Notifications — Unopened only

Unopened exists to tell you who asked you something and never got an answer, so it needs notification access: the Android permission that lets an app see the notifications your phone shows you. It is not a runtime pop-up — you grant it by hand in system settings, and you can withdraw it there at any moment, after which the app sees nothing new. We want to be exact about what it does and does not mean:

• What it reads: the notifications your phone displays — who sent them, the text shown, which app posted them, and whether you opened, swiped or replied. It reads nothing else on your phone: not your messages inside other apps, not your contacts, not your files, not your location.
• The sorting happens on your phone. A small model shipped inside the app decides whether something asked you a question. It runs on your phone's own processor. Nothing is sent anywhere to be understood, and nothing you receive is used to train any model of ours.
• It cannot upload anything. Unopened has no internet permission, so it is technically incapable of transmitting a notification, a message or a statistic. You can verify this yourself in Android Settings › Apps › Unopened › Permissions.
• Where it is kept: the app's private storage on your phone, which other apps cannot read, for the retention window you choose in Settings — 7 days, 30, 90 or a year. Anything older is deleted automatically each night. “Delete everything” in Settings removes it all immediately, and uninstalling the app removes it with the app.
• One-time codes. Android hides the content of notifications it identifies as containing one-time passcodes before an app like this ever sees them; such rows appear with their text redacted. Unopened also skips its own notifications.
• Nothing is shared. Content leaves the phone only if you export it yourself — and the export exists only in development builds handed out for testing, never in the version on Google Play.
• The evening summary is a notification the app posts to itself at a time you choose, and only when somebody is actually waiting. It is off until you turn it on, and Android asks for the notifications permission at that point.

Speech and practice history: Yappo only

Yappo is a pronunciation coach. It listens to you say a word or a sentence and scores each sound. It needs the microphone permission for that, and Google Play billing so that its optional paid tier, Yappo Plus, can be bought. It has no internet permission. You can verify this in Android Settings › Apps › Yappo › Permissions. We want to be exact about what it does and does not mean:

• The microphone is used only while you hold the button and say something, and is released when you let go or leave the app.
• Your voice is scored on your phone. A speech model shipped inside the app does the scoring, in memory. Nothing you say is sent anywhere, and the app has no internet permission with which to send it.
• Recordings are not saved. In the version on Google Play the audio is not written to storage. Your last attempt is held in memory only, so that you can play it back.
• What is kept on your phone, in the app's private storage that other apps cannot read: your practice history (each scored attempt with its date and time, the sentence, the score and the verdict on each sound, including any text you typed yourself); the words you told Yappo how to pronounce; your settings (speed, theme, best streak); and a small record of whether Yappo Plus is active (described below). None of it is sent to us.
• Year of birth. Yappo asks once for the year you were born. It is used only to decide whether to switch on the parent check described under Children below. It is kept on your phone, in a file of its own, and is not included in Android's cloud backup, in the progress file, or in any message you send us. If you restore your phone from a cloud backup, Yappo asks the question again.
• Android backup. If you have Android's system backup turned on, your practice history and settings may be included in your own Google account backup, under Google's privacy policy rather than ours. The year of birth, the words you added, the Plus record and any crash report are not. A direct phone-to-phone transfer (a local copy to a phone you are holding) copies the app's private files, the year of birth included. We have no access to your backup.
• The progress file. “Save a copy” in Yappo writes your progress to a file, or hands it to another app you choose, so you can move it to a new phone. It holds your scored attempts, your streak, your speed and theme, and the words you added. It holds no recordings, no purchase and no year of birth. It leaves your phone only if you save or send it yourself, and then the receiving app's own privacy policy applies.

Feedback and crash reports: Yappo only

Yappo has a “Help us improve” screen and can offer to send a crash report. Neither is sent by the app. Each one opens your own email app with a message addressed to contact@onllm.dev. Yappo lists what the message will contain before it opens your email app, you can read all of it there, and nothing goes until you press send.

• A feedback message contains what you type, and only what you switch on: your device (Yappo version, Android version and phone model; on by default); your ten most recent attempts (sentence, score and the sounds to fix; off by default); and, for a problem or a wrong score, a sound analysis of your last attempt (the probabilities of each sound as the model heard it, which cannot be played back as speech; off by default) and your last recording (your voice as you said it; off unless you switch it on). A message about a wrong score also carries the sentence and the verdict and score of each sound in your last attempt.
• A crash report is written on your phone if Yappo closes unexpectedly, and the next time you open the app it offers to send it. It holds the Yappo and Android versions, the phone model, the time, the technical description of the error, and up to ten short notes about recent problems the app recovered from. It holds no recordings and none of your practice history. If you dismiss it, it is deleted.
• What we receive is that email, including your email address and anything you wrote or attached. We use it to look into the problem, to reply to you and to improve Yappo.

Purchases: Yappo only

Yappo is free to use. Yappo Plus, which lifts the limit on your own words and on how far back your history goes, is sold through Google Play as a yearly subscription or as a one-time purchase. Payment is handled entirely by Google. We receive no card number, no payment details and no Google account details. Yappo only asks the Play Store app on your phone whether you own Plus, and keeps a small record of the answer (which tier, whether it renews, when it ends and when it was last checked) so that it can show it. On a new phone your purchase comes back through your Google account. Family sharing of Plus is not offered on Android.

Deleting everything: Yappo only

Settings › “Delete everything” in Yappo erases from your phone your attempts, your streak, the words you added, your year of birth, your settings, the Plus record and any crash report, and Yappo goes back to how it was when first installed. A purchase is not affected, because it belongs to your Google account, not to the app. Uninstalling Yappo removes its files as well.

Your settings

Preferences such as your chosen units, theme, calibration offsets and alert thresholds are saved locally so the app remembers them. If you have Android's system backup enabled, these settings may be included in your own Google account backup, under Google's privacy policy rather than ours. We have no access to that backup.

Data sharing and third parties

We share no data with anyone, because we hold none. Our apps contain no advertising networks, no analytics providers, no attribution SDKs and no social media SDKs.

An app may offer to open an external page — for example “Rate this app” which opens the Google Play Store, or a link to onllm.dev in your browser. Following such a link takes you to a third-party service that has its own privacy policy. Google Play's policy is available at policies.google.com/privacy.

Data retention and deletion

Our apps send us nothing, so there is nothing for us to delete and no deletion request to make. The one exception is an email you choose to send us yourself, such as Yappo feedback; if you want one deleted, write to contact@onllm.dev. Anything an app has stored on your device — settings, calibration, recorded sessions, the notification history in Unopened, the practice history in Yappo — is removed when you clear the app's storage from Android Settings, or when you uninstall the app. Unopened also deletes its own history as it ages past the window you chose, and has a button that deletes all of it at once. Yappo has a “Delete everything” button too.

Children

Our apps are suitable for a general audience and are not directed at children under 13. Because they collect no data from anyone, they collect no data from children either. We do not knowingly collect personal information from children, and given the design of these apps, we could not do so.

Yappo is meant for people aged 13 and over, but a younger person may still install it, and it is built to look after them. It asks once for a year of birth, which stays on the phone (see above). If that year means the person is under 13 (worked out from the year alone, so it errs on the side of caution), a parent check, a sum that must be answered, comes before any purchase step and before any feedback or crash report is opened in the email app; the message never offers a sound analysis or a recording, and the device line is off unless the person switches it on. As for everyone, Yappo collects nothing from children: it has no internet permission, no account, no advertising and no analytics, and a child's practice stays on the phone. A parent or guardian who believes a child has sent us a message can write to contact@onllm.dev and we will delete it.

Security

The strongest security measure available is not to hold data in the first place, and that is the one we rely on. Data stored on your device is protected by Android's application sandbox and by your device's own encryption.

Your rights

Privacy laws such as the GDPR, the UK GDPR, the CCPA and India's DPDP Act give you rights to access, correct, delete and port your personal data, and to object to its processing. These rights are directed at organisations that hold personal data about you. We hold none, so there is no data to access, correct, port or delete. You remain in full control of everything stored locally on your device.

We do not sell or share personal information, as those terms are defined by the CCPA, and we never have.

Changes to this policy

If this policy changes, the updated version will be published at this address with a new effective date. Material changes will also be described in the app's release notes on Google Play. Continuing to use an app after a change means you accept the updated policy.

Contact

If anything here is unclear, or you believe an app is behaving differently to what is described, please write to contact@onllm.dev and we will respond.