Privacy Policy — 1Byte Systems

Apps covered: 1B Terminal (com.onebytesystems.terminal), 1B Files (com.onebytesystems.files), 1B Docs (com.onebytesystems.docs), 1B Pass (com.onebytesystems.pass), 1B Music (com.onebytesystems.music), 1B Recorder (com.onebytesystems.recorder), 1B Mail (com.onebytesystems.mail), 1B Weather (com.onebytesystems.weather) and the games 1B Rotate (com.onebytesystems.rotate), 1B Mahjong (com.onebytesystems.mahjong), 1B Fold (com.onebytesystems.fold) and 1B Zombie Hunter (com.onebytesystems.zombie).
Last updated: October 17, 2026
Developer: 1Byte Systems (Alberto Martín Cid) – 1bytesystems@gmail.com – https://1bytesystems.com

Summary

Our apps do not collect, sell or share your personal data. They contain no ads, no analytics and no third-party tracking SDKs. Everything you create in the apps stays on your device, and the apps only connect to servers that you configure yourself — except 1B Music, which looks up covers, song details and lyrics in public music databases (something you can turn off) and sends your listens to Last.fm or ListenBrainz only if you connect your own account, as described below. The optional 1Byte account on our website, used for Pro licences, has its own section. 1B Mail also looks up your provider's settings in public directories and, on computers, checks our website for updates, as described below. 1B Weather gets its forecasts from our own weather server, which receives only an area of about 2 km around the places you look at (never your exact position) and keeps no records per user, as described below.

1B Terminal

Data stored on your device: the hosts, usernames, passwords, SSH keys, snippets, known host fingerprints and settings you enter. Passwords and private keys are encrypted with a key kept in the Android Keystore. This data never leaves your device except when you use it to connect to a server.
Network: the app connects only to the SSH servers you add. What you send to those servers is governed by their owners, not by us.
Voice input: the app does not use the microphone. If you dictate with your keyboard (for example Gboard), speech recognition is done by that keyboard app under its own privacy policy; 1B Terminal only receives the resulting text.
Permissions: Internet and network state (to connect to your servers); foreground service and notifications (to keep your SSH sessions alive in the background and show their status); vibration (keyboard feedback).

1B Files

Your files: the app reads and manages the files on your device's storage so you can browse, copy, move, compress, clean up and delete them. This happens entirely on your device. Nothing is uploaded to us.
Data stored on your device: settings, favorites, the trash (kept for 30 days), secure folder contents, and the remote servers you add (their passwords are encrypted with a key kept in the Android Keystore).
Network: the app connects only to servers you configure (SFTP, FTP/FTPS, SMB, WebDAV) and to cloud apps you choose through the Android file picker. The "Access from PC" feature starts a web server only on your local Wi-Fi network or hotspot, and only while you keep it on: a computer gets in with the 6-digit PIN shown on your phone (or a direct link with a 128-bit key), which gives that browser a session cookie. The server turns itself off after 15 minutes without use, and nothing is sent to the internet.
Permissions: All files access (core file manager functionality); query installed apps (to show and manage your apps and detect leftover APK files); install and uninstall packages (only when you tap an APK or ask to uninstall an app); usage access – optional (to show the real size and cache of your apps); Internet and network state (remote servers and Access from PC); foreground service and notifications (long file operations and Access from PC).

1B Docs

Your documents: the app opens, creates and edits the documents you choose (text documents, spreadsheets, presentations, PDF and plain text). All processing happens on your device. Nothing is uploaded to us or to anyone else.

Data stored on your device: settings, the list of recent and favourite documents, cached page thumbnails, and your saved signature for signing PDFs. You can clear recents and the thumbnail cache in Settings.

Network: none. The app does not request the Internet permission.

Permissions: All files access – optional (to list the documents on your device; without it the app works through the Android file picker and with files shared by other apps); storage access on Android 10 and earlier.

1B Pass

Data stored on your device: the logins, passwords, payment cards, secure notes, identities, Wi-Fi keys, two-step (TOTP) secrets and settings you enter. All of it is encrypted on the device with AES-256-GCM, using a key derived from your master password with Argon2id; optional fingerprint or PIN unlock uses keys kept in the Android Keystore.
Network: none. The app does not request the Internet permission and never transmits anything. Data leaves the app only when you choose to: encrypted backups or CSV exports written to the location you pick with the system file picker, and values you copy or autofill into other apps.
Autofill: the app uses the standard Android Autofill Framework to fill in and save sign-ins in other apps and browsers. This happens on your device.
Camera (optional): used only to scan two-step QR codes and for the optional intruder photo, which is off by default. Images are analysed on the device, and intruder photos stay in the app's private storage.
Permissions: camera – optional (QR codes and intruder photo); biometric (fingerprint unlock); wake lock and run at startup (to schedule the optional automatic backup). Android cloud backup of the app's data is disabled.

1B Music

Your music: the app reads the audio files on your device (and the folders you add with the system folder picker) to build your library and play it. Your audio files are never uploaded anywhere.
Data stored on your device: your library database, playlists, play counts and listening history, favourites and ratings, cover art and artist photos, recent replies from the online services below (kept for up to 30 days so the same question is not asked twice), equalizer and other settings, the music servers you add (their passwords or access tokens are encrypted with a key kept in the Android Keystore) and, if you connect them, your Last.fm session key and ListenBrainz token (kept in the app's private storage).
What leaves your device to identify your music: to find the right covers, song details, artist photos and lyrics, the app sends text taken from your tags or, when tags are missing, from file names: song titles, artist and album names, track numbers, durations, barcodes and MusicBrainz identifiers when your tags have them. For songs it cannot identify that way, it sends an acoustic fingerprint — a short numeric summary of the sound, calculated on your device, from which the audio cannot be rebuilt — together with the song's duration. It never sends your audio or your files, and it sends no account, device identifier or advertising ID; the requests only name the app and its version.
Which services, and what for: MusicBrainz and Cover Art Archive (song details and covers), AcoustID (acoustic fingerprints), Apple iTunes Search (details and covers; it also receives your device's country, to search the right store), Deezer, Discogs and Last.fm (details and covers), fanart.tv (covers and artist images; it only receives MusicBrainz identifiers), Wikidata and Wikimedia Commons (artist photos) and LRCLIB (lyrics, when you open them). Each service receives your IP address as part of the connection and handles it under its own privacy policy: MetaBrainz Foundation (MusicBrainz, Cover Art Archive), AcoustID, Apple, Deezer, Discogs, Last.fm, fanart.tv, Wikimedia Foundation and LRCLIB.
You decide: in Settings › Covers and metadata, "Search covers and info on the Internet" can be set to Wi-Fi only (the default), Always or Never. With Never, none of the lookups above happen (lyrics included); the app keeps playing everything and uses the covers inside your files and folders.
Scrobbling to Last.fm and ListenBrainz (optional): only if you connect your own account in Settings. To connect Last.fm you enter your username and password, which are sent only to Last.fm to get a session key and are not stored; for ListenBrainz you paste your user token. From then on, for each song you listen to (more than half of it, or 4 minutes), the app sends that service the song title, artist, album, album artist, track number, duration, MusicBrainz identifiers when known and the time you listened, plus a "now playing" notice when a song starts. Listens wait on your device until there is a connection. You can pause or disconnect each service at any time. What you send there is governed by Last.fm and the MetaBrainz Foundation (ListenBrainz).
Your music servers: if you add a Navidrome/Subsonic, Jellyfin, Emby or Plex server, the app connects directly to it (and, for Plex, to plex.tv to sign in) with the credentials you enter, streams your music from it and sends it back play events, favourites and ratings. Nothing goes through us. Unencrypted (http) connections are only allowed to addresses on your local network. That data is governed by the server's owner, not by us.
Casting: to play on a Chromecast or another Google Cast device, the app uses Google Cast, part of Google Play services, under Google's privacy policy. The Cast device receives the song, its title, artist, album and cover: from your music server or, for songs on your device, from a temporary server that the app runs on your local network only during the Cast session, protected by a random key.
Backups: if you make one, the backup file (playlists, listening history, favourites, ratings, edits and settings) is saved where you choose with the system file picker. It contains no passwords or tokens. Android cloud backup of the app's data is disabled.
Permissions: music and audio (to read your music files; storage on Android 12 and earlier); foreground service and notifications (to keep playing in the background with playback controls, and to keep finding covers while the screen is off); Internet and network state (your servers, the online services above and the Wi-Fi-only setting); wake lock (uninterrupted playback).

1B Recorder

Microphone: the app records audio with your device's microphone (or a Bluetooth or wired microphone you connect) only while you are recording or dictating, and always shows a notification while it does.
Data stored on your device: your recordings, transcripts and your edits, markers, speaker names, summaries and tasks, folders, the trash (kept for 30 days) and settings. Recordings are encrypted on the device as you record, in one-minute pieces. Transcription, speaker separation, summaries and tasks are all computed on your device. An optional lock with your fingerprint or screen lock protects access to the app.
Remembered voices (optional): only if you turn on "remember voices", the app keeps voiceprints — numeric summaries of a person's voice, used to suggest names the next time — encrypted on your device. They are never sent anywhere.
Network: none. The app does not request the Internet permission and cannot transmit your recordings, transcripts, summaries or voiceprints. Nothing is sent to 1Byte Systems.
Language models: the language models are delivered by Google Play (Play Asset Delivery) when you choose a language, as part of the app download. Google Play may process that download like any other app download, under Google's privacy policy; it receives none of your audio or text.
Wear OS watch: recordings made with the watch app go from the watch to your own phone over the Wear OS data layer (part of Google Play services), encrypted end to end with a key created for each recording, and are transcribed on the phone.
Import, export and backups: audio you share with the app or import (for example, voice messages from WhatsApp or Telegram, audio and video files, or recordings saved by your phone's own call recorder) is processed on the device. The app does not record phone calls. Exports (text, subtitles, documents and audio) and encrypted backup files go only where you choose with the Android share sheet or file picker; backups are protected with your password and you keep them. Android cloud backup of the app's data is disabled.
Purchases: 1B Recorder Pro is a one-time purchase handled by Google Play. We do not receive your payment details.
Permissions: microphone (recording and dictation); foreground service, notifications and wake lock (to keep recording with the screen off, with its notification, and to finish transcribing in the background); audio settings (Bluetooth microphones); biometric (optional fingerprint lock); vibration. On the watch: microphone, foreground service, notifications, wake lock and vibration.

1B Mail

1B Mail is an email app for Android, Windows and Linux. It connects directly from your device to the mail servers of the accounts you add. 1Byte Systems has no servers for 1B Mail and never receives your messages, your contacts or your passwords.

Data stored on your device: your accounts and their settings, the messages, attachments and folders downloaded from your mail servers, a search index, the addresses you write to (for suggestions), your signatures, rules and settings. Templates, scheduled messages and snoozed messages are kept as messages in folders of your own mailbox, so your other devices can see them.
Passwords and sign-in tokens: kept in an encrypted vault (AES-256-GCM) whose key is protected by the Android Keystore, the Windows Credential Manager or the Linux Secret Service. On Android, the app's data is excluded from cloud backups and device transfers.
Your mail servers: the app connects only to the IMAP and SMTP servers of your accounts, encrypted with SSL/TLS or STARTTLS (an unencrypted connection is used only if you choose it in the server settings). If a server's certificate cannot be verified, it is accepted only after you check and confirm its fingerprint. What you send and receive is handled by your email provider under its own policy.
Setting up an account: to find your server settings automatically, the app sends the domain of your address (the part after @) to Mozilla's public directory of email providers (autoconfig.thunderbird.net) and to DNS, and asks your provider's own configuration address, which receives your email address.
Signing in with Google or Microsoft (optional): you sign in on Google's or Microsoft's own pages (through Google Play services on Android). The access tokens are stored only on your device, in the vault above, and are used only to reach your own mailbox. 1B Mail's use and transfer of information received from Google APIs adheres to the Google API Services User Data Policy, including the Limited Use requirements: your Gmail data stays on your device, is never sent to us, never used for advertising and never read by people.
Opening messages: messages are shown in an isolated viewer that loads nothing from the internet by itself. Remote images are downloaded only if you choose to show them (for one message or for a sender you trust), without cookies. Links open in your browser.
Unsubscribing (optional): when you ask to unsubscribe from a mailing list, the app sends the unsubscribe request that the list offers: a one-click request to its secure web address, or an email to its unsubscribe address.
Notifications and Instant mail (Android): new-mail notifications are created on your device. Optional Instant mail, off by default, keeps a connection open to your own mail servers while a permanent notification is shown.
Moving accounts between devices: "Send to phone" and "Bring accounts from my computer" move your account settings (and passwords, only if you choose) directly between your computer and your phone over your local network, end-to-end encrypted, or in a file you create. The camera is used only to scan that QR code. On computers, the app can also read the accounts saved by Thunderbird or Outlook on the same computer when you ask it to.
Updates and 1B Mail Pro (computers): the Windows and Linux app checks 1bytesystems.com for updates at most once a day (you can turn this off in Settings); the request identifies only the app. If you activate 1B Mail Pro with your 1Byte account, the app sends our server the name of the device, its platform and the app version, and checks the licence from time to time, as described in "1Byte account" below.
No analytics: no ads, analytics, crash reporting or tracking. Error logs stay on your device.
Removing data: removing an account deletes its local data, and uninstalling the app deletes the rest. Messages on your mail servers are not affected.
Permissions (Android): Internet and network state (your mail servers); notifications; run at startup and wake lock (periodic checks and Instant mail); foreground service (Instant mail, only while it is on); camera – optional (QR code); Google Play billing (for 1B Mail Pro).

1B Weather

1B Weather is a weather forecast app for Android. To show the forecast, it connects only to our own server, weather.1bytesystems.com, which 1Byte Systems runs (today our own server in Spain; later a rented server in the European Union with the same software). It is reached through Cloudflare's network, which carries the connection and caches the forecast responses, which are the same for everyone in an area.

What our server receives: for a forecast, the area of the place you look at: its coordinates, rounded on your phone to a grid of 0.02° (a cell of about 2 km), never your exact position; to search for a city, the text you type and the app's language; and, as with any connection, your IP address (seen by Cloudflare's network and by our server) and a technical header that identifies the app and its version ("1BWeather/version").
What it does not keep: there are no logs per request or per user: not your IP address, not the places you ask for and not your searches. To limit abuse, your IP address is used only in memory, as a fingerprint with a random salt that changes whenever the server restarts, and it is never written to disk. We keep only aggregate counters (number of requests per minute and per hour), with no personal data. The forecast cache is stored per cell, the same for everyone, without knowing who asked for it.
Weather data and place names: our server asks MET Norway (the Norwegian Meteorological Institute) for the forecast of each cell, identifying itself as 1Byte Systems; MET Norway never sees your IP address or anything about you. Weather data comes from MET Norway under the CC BY 4.0 licence. Place names come from a copy of GeoNames (CC BY 4.0) kept on our server, so your searches are not sent to anyone else.
Approximate location (optional): the app asks for Android's approximate location permission only when you tap "Use my approximate location". That location is rounded on your phone to the same cell of about 2 km before it leaves it, and is used for the forecast and to find the name of the nearest place. The app never uses precise location and never accesses your location in the background.
Data stored on your device: your saved places, your settings and the latest forecasts (so the app and its widgets work without a connection), in the app's private storage. They are deleted when you uninstall the app.
Morning summary (optional): if you turn it on, a daily notification with the day's summary for your first place is created on your phone.
No ads, analytics or account: no ads, no analytics, no crash reporting services and no third-party SDKs that use the network; no account and no cookies. Nothing is sold or shared with third parties. Connections are always encrypted (HTTPS/TLS); unencrypted connections are not allowed.
Purpose, legal basis and retention: the data above is processed only to provide the forecast and the search you ask for (the service you request) and to protect the service against abuse (our legitimate interest in keeping it secure). No records per user are stored, so there is nothing about you to keep or delete.
Permissions: Internet and network state (to talk to our server and know whether there is a connection); approximate location – optional (only when you tap "Use my approximate location"); notifications – optional (morning summary, Android 13 and later); run at startup and wake lock (so the widgets keep refreshing after a restart). Never precise or background location, and no exact alarms.

Games: 1B Rotate, 1B Mahjong, 1B Fold and 1B Zombie Hunter

Data stored on your device: your game progress, scores, coins, unlocked items and settings. This data never leaves your device.

Network: none. The games do not request the Internet permission and work fully offline. They contain no ads and no in-app purchases.

Permissions: vibration (haptic feedback), where used. No other permissions.

1Byte account (licences on our website)

The 1Byte account is optional: you only need it to see and activate Pro editions on your computers. It lives at 1bytesystems.com/account and is served by our own server in Spain (api.1bytesystems.com), reached through Cloudflare's network. It never sees your email messages, your mail accounts or anything you create in the apps.

What we keep: your email address; the name you choose to show on your licences (optional); the language for our emails; if you use "Continue with Google", your Google account identifier; your editions, activation codes redeemed and licences; the devices where you activate Pro with your account (the name the app sends, platform, system, app version and dates); your open sessions (date and browser name, such as "Firefox · Linux"); and a log of changes to your licences.
What we don't keep: passwords (there are none: we email you a one-time code), your IP address in readable form (only a keyed hash, rotated daily and deleted after 48 hours, to stop abuse), or anything from your mailboxes.
Sign-in emails: codes and sign-in links are sent from 1bytesystems@gmail.com through Google's mail service, so Google processes that message like any email. The code expires after 10 minutes and works only once.
"Continue with Google" (optional): Google tells us your email address, name and account identifier, under Google's privacy policy. We ask for nothing else.
Cookie: when you sign in, api.1bytesystems.com sets a single essential cookie (__Host-1b_session) that keeps you signed in for 30 days from your last visit. It is not used for anything else, and it is deleted when you sign out. This website itself sets no other cookies.
Purpose and legal basis: to provide your account and your licences (performance of a contract). No advertising and no profiling.
Retention: sign-in codes, 24 hours; sessions, 30 days after their last use; your account, until you delete it. Accounts without licences that have not been used for 24 months may be deleted after notice.
Your choices: from your account page you can download all your data (a JSON file), sign out everywhere, remove devices and delete your account, confirmed with a code sent to your email. When you delete it, we erase your email, name, sessions and devices and the text of your licences; we keep only pseudonymous records (licence and edition identifiers and dates) so licences can still be revoked and to meet legal obligations. Licences already activated in your apps keep working.

Data sharing and retention

Apart from the 1Byte account and the 1B Weather server described above (which keeps no records per user), we do not receive, store, sell or share any data from our apps. Data kept on your device stays there until you delete it or uninstall the app. Android's own backup system may include app settings in your personal device backup, which is governed by Google's privacy policy.

Children

Our apps are general-purpose tools not directed at children under 13.

Your rights (GDPR)

Our apps do not send us personal data that we keep (1B Weather's requests to our server are not stored per user), so for them there is nothing for us to access, correct or delete. For the 1Byte account, you can access, download, correct and delete your data yourself from your account page, or by writing to us. You can remove all app data at any time from Android settings or by uninstalling the app. For any question, write to 1bytesystems@gmail.com.

Changes

If this policy changes, we will update this page and the "Last updated" date.

1Byte Systems – Privacy Policy