Alien Apps

Sachwert-Tresor (Hard-Asset Vault)

Encrypted vault for Bitcoin, gold & silver

Your wealth is nobody's business. A local, encrypted vault for your Bitcoin, gold and silver holdings – fully offline. No cloud, no server, no price API reading along. Nothing leaves your device in plain text.

• AES-256-GCM encryption, key derived from your passphrase with Argon2id (since v3.0) – makes brute-forcing costly
• Optional two-factor authentication (TOTP)
• Optional fingerprint unlock (app, since v3.0) – after every restart the passphrase first (optional since v3.2, box when enabling, off by default), and it switches itself off when a new finger is enrolled
• Precious metals as count × unit size – bars and coins tracked cleanly
• Manual price entry: no data leaking to external price services
• Wealth over time: every price you enter is remembered with its date, the history tab shows value next to cost basis – still no price lookups
• Cross-device sync via Syncthing – peer-to-peer, no middleman
• Entries in EUR, USD or CHF, display in BTC or sats – no price lookups
• Estate appendix: one sheet with your net holdings for the heir package, quantities only
• Since v3.3: also for the Linux desktop – a Flatpak without network permission and without file access, with a GPG-signed checksum, backups interchangeable between phone and desktop
• Since v3.5: confirmations as in-app dialogs instead of the Android system dialog (which did not inherit the screenshot protection), "Undo" after deleting an entry
• Since v3.6: if the app locks while the file picker is open, the chosen file is not lost – the import continues after unlocking (.vault and CSV)

App only, deliberately no web version – full hardening in the Android app: no INTERNET permission (only system permission: fingerprint), FLAG_SECURE, no cloud backup and no transfer when switching phones – operating-system-level protection a website cannot offer. On the Linux desktop: a Flatpak without network and without file access, limits on the vault page.

Android / GrapheneOS · Linux (Flatpak) · open source (MIT) · no account, no server

Ausgaben-Tracker (Expense Tracker)

Minimal, fully offline expense tracker

A budget book without banking-app snooping. Keep an eye on your spending – no account, no server, no tracking. All data stays encrypted on your device.

• Monthly and annual overview at a glance
• Fixed-cost management for recurring expenses
• Debts tab: note open payments with due date and tick them off
• Breakdown by category, search and filter, your own categories (since v1.7)
• Settings: selectable auto-lock, colour theme, built-in manual, German/English following the system language (since v1.7)
• Pickers and the search clear button in the app's own style instead of grey system lists (since v1.8)
• Confirmations as the app's own dialog instead of the Android system dialog (which was outside the screenshot protection), "Undo" after deleting an expense (since v1.9)
• No third-party autofill: another password manager does not see the master password field and cannot offer to save it (since v1.10)
• CSV export for your own analysis, encrypted .vault backup
• AES-256-GCM encryption with master password, not a single Android permission

Android / GrapheneOS · open source

Alien Fitness

Minimal, fully offline workout tracker

A training log that belongs to you. A personal workout tracker – training plans, live logging and progress, without a fitness platform recording your health data.

• Create your own training plans or use the built-in ones: strength (Push / Pull / Legs) and HIT (Tabata, Power)
• Free workouts: start empty, add exercises on the fly, save when done
• Live logging with rest and HIT interval timer, "last time" comparison and corrections
• Resume interrupted workouts, per-session training notes
• Progress charts per exercise (max weight / reps over time)
• Exercise library with images, muscle groups and equipment
• JSON backup to save and migrate (merge or replace)

Android / GrapheneOS · open source · no account, no server, no internet permission

Alien Pass

Offline password manager without internet permission

The master key stays with you. A local, encrypted password manager – fully offline. No account, no sync server, no telemetry. The app does not even have an internet permission.

• Logins, encrypted notes, cards and bank accounts (IBAN, BIC, PIN), sorted into categories
• Argon2id + AES-256-GCM, file header authenticated
• Password generator with characters or EFF dice words, TOTP codes per entry
• Clipboard auto-clear, flagged sensitive, auto-lock also in the background
• Encrypted backup and merge between devices (Syncthing)
• Migration from Proton Pass straight from the PGP-encrypted export; CSV from Google Password Manager/Chrome, Apple Passwords, Firefox, KeePassXC, Bitwarden, LastPass, 1Password and NordPass (since v1.10 detected by format, folders and tags become categories)
• Since v1.2: optional fingerprint unlock via the Android keystore — passphrase required after every restart (optional since v1.8), "Lock now" as the deliberate bolt
• Since v1.3: account entry type; no more age warning for passwords (forced rotation is an anti-pattern)
• Since v1.4: up to eight freely named, always-secret extra fields per entry (app PIN, phone password …), e-mail field next to the username, generator right inside the entry form
• Since v1.5: trash – deleted entries stay restorable for 30 days (up to 200 entries, only on the device where they were deleted), pickers in the app's own style
• Since v1.6: a more honest strength meter – spots predictable patterns such as years, keyboard runs and common words (also P4ssw0rd), flags them in the list and asks before accepting a weak vault passphrase
• Since v1.6.1: a warning when a fingerprint was newly enrolled in Android – even across a restart – and the failed-attempt brake keeps counting across app restarts
• Since v1.7: also for the Linux desktop – a Flatpak without network permission and without file access, with a GPG-signed checksum, backups interchangeable between phone and desktop
• Since v1.8: Android – "fingerprint also after a restart" box (off by default); desktop – quick unlock with a PIN after a lock (in memory only, at most 24 hours, honestly assessed); a third internal audit of the desktop branch
• Since v1.9: confirmations as in-app dialogs instead of the Android system dialog (which did not inherit the screenshot protection), "Undo" after deleting, multi-select – several entries at once to the trash, into a category or as favourites

App only, deliberately no web version: on Android no internet permission (only the fingerprint sensor), FLAG_SECURE, no cloud backup – hardening at the operating-system level; on the Linux desktop a Flatpak without network. Details on the Alien Pass page.

Android / GrapheneOS · Linux (Flatpak) · open source (MIT) · no account, no server

Alien Notes

Encrypted offline notes and checklists without internet permission

Your notes never leave the device in plaintext. A local, encrypted notes and checklist app – fully offline. No account, no server, no telemetry. Sister app of Alien Pass with the same architecture and the same hardening.

• Notes (free text up to 100,000 characters) and checklists (up to 200 entries, "done to the bottom", "clear ticks") – switch a note between the two, lines become entries and back
• No save button: the app saves as you type (after 1.5 s) and when you leave the note – encrypted, the whole file every time
• Markdown preview per note (off by default): a small own subset, no third-party renderer, no HTML, links stay plain text; cheat sheet in the editor
• Categories like folders (rename them, too), favourites, pinned notes at the top, an "Open" chip for checklists with unfinished entries, search across title, text, checklist entries and category
• Since 1.1: moving from Standard Notes (decrypted backup as ZIP or text file, 2FA entries are never imported), several notes at once to the trash, into a category or as favourites, "Undo" after deleting, "no preview" per note, three font sizes, confirmations as in-app dialogs instead of system dialogs
• Clipboard auto-clear (30 s by default, can be switched off) and on lock, flagged sensitive on Android. With "Lock in background: immediately" the copied note stays until the chosen time runs out so it can still be pasted into another app (since 1.3).
• Locking more relaxed than a password manager: by default no lock after inactivity, in the background after 30 minutes – both adjustable up to "never" / "immediately". With "immediately" the Android app also locks while the file picker is open; unlock within five minutes and the import continues with the chosen file (since 1.2).
• Trash: deleted notes stay restorable for 30 days, up to 200 at a time, showing only title, type and date
• Encrypted backup (.notes) and merge between devices, also between phone and Linux desktop (e.g. via Syncthing)
• Aegis hurdle, fingerprint unlock (Android) and quick unlock by PIN (desktop) – optional, taken over from Alien Pass (Aegis without QR)
• Screenshots and app-switcher preview blocked by default (FLAG_SECURE), can be switched off in Settings – notes are not always secret
• No Android autofill, not even third-party (since 1.4): the app keeps its WebView out of the autofill framework – a password manager set up as the autofill service never sees the passphrase fields and cannot offer to save them
• Also for the Linux desktop – a Flatpak without network permission and without file access, with a GPG-signed checksum
• Two internal security audits (0.1: the surface new compared to Alien Pass plus the file store; 1.1: Standard Notes import, dialog, undo, multi-select) – all findings fixed before release (no independent audit)

App only, deliberately no web version: on Android no internet permission (only the fingerprint sensor), FLAG_SECURE, no cloud backup – hardening at the operating-system level; on the Linux desktop a Flatpak without network. Details on the Alien Notes page.

Android / GrapheneOS · Linux (Flatpak) · open source (MIT) · no account, no server

BTC Steuertool

Bitcoin tax report for the German tax office – no internet permission, your data stays with you

Your tax data does not end up on someone else's server. CSV exports from BitBox and brokers in, annual report under § 23 EStG out – calculated entirely on your device. No account, no upload, no telemetry. The same open-source calculation core as the CLI tool and the web version.

• FiFo per wallet (German Federal Ministry of Finance circular of 6 March 2025, para. 62), every exchange account counting as a wallet of its own – on transfers between your own wallets, purchase date and cost travel along (a reading disclosed in the evidence document); one-year holding period counted by calendar date (§§ 187, 188 BGB) and the exemption limit (600 EUR up to 2023, 1,000 EUR from 2024)
• BitBox, 21bitcoin, Bison, Swissquote, Strike, Pocket, Bisq 1 (German or English interface) plus manual buys and sells; other exchanges via a CoinTracking or Blockpit export (format not yet confirmed against real exports, the report warns) – brokers are detected from the file contents, ZIPs are unpacked; unknown files block the calculation instead of silently missing
• Since v1.3: every file is checked for its required columns before reading – a renamed column stops the run with file, line and column instead of silently dropping data; a byte-order mark (e.g. after saving in Excel as "CSV UTF-8") is now read correctly
• Fees paid in bitcoin (network, withdrawal, Bisq trading fee) treated as a disposal of the fee amount, gifts and donations as a reduction of holdings
• noKYC kept strictly apart: its own FiFo pool and its own internal report, never part of the documents for the tax office
• Tax report, formal tax evidence, buys and sells as CSV – saved through the save dialog
• ECB exchange rates and BTC daily closing prices built in – the app downloads nothing after installation
• Android: no internet permission, screenshots blocked (FLAG_SECURE), no backup of app data
• Also for the Linux desktop – as a Flatpak without network permission and without file access, with a GPG-signed checksum
• In-app guide (German/English); internal security audit before the release, all findings fixed (no independent audit)

Also in the browser and as a CLI: the web version fetches its code from the server on every visit, the CLI runs from the repo. Everything on the tax tool page. Reports are in German, they are meant for the German tax office. No tax advice – a calculation aid.

Android / GrapheneOS · Linux (Flatpak) · open source (MIT) · no account, no server