Cobalt icon

Cobalt

Hanan Bhatti
Note Task Tools
Version
2.1.2
Size
5.3 MB
Requires
Android API 24+
4.4 / 5 · 14,722 ratings 90,049 downloads

Updated Oct 17, 2026

Quick answer

Universal offline-first note capture and personal knowledge archive

Cobalt is an offline-first personal archive and capture app for Android. It stores links, notes, images, audio clips, code snippets, and movie/anime watchlists in a local Room database without requiring an account.

Capture Methods: - Android Share Target: Save text, URLs, images, and videos directly from other apps via the system share sheet. - Floating Overlay: Access a screen-edge panel to write quick notes, capture links, or trigger OCR without leaving your current app. - Screen Region OCR: Capture a screenshot or crop a region on screen using MediaProjection to extract text and links. - Quick Settings Tile: Launch OCR capture directly from the system Quick Settings panel. - Voice Notes: Record audio memos with real-time waveform display, stored locally on device. - Home Screen Widgets: View recent captures or trigger capture actions from your home screen.

Organization & Viewing: - Supported Item Types: Links (with metadata previews), Markdown text notes, Photos/Images, Video clips, Code snippets, Audio recordings, and Movies/Anime. - Folders & Archive: Organize items into custom folders or archive them to remove them from the main feed while keeping them stored. - Search & Filters: Search across titles, content, extracted OCR text, and URLs, with filter chips for each media type. - Media Hub: Track movies and anime with watch statuses (Plan to Watch, Watching, Completed), genres, ratings, and release years. - Storage Management: View local storage usage broken down by media type, with options to delete cached files.

Network & Privacy Disclosures: The FOSS build stores all data locally on your device. It does not include analytics, tracking SDKs, or background synchronization services. Certain optional features connect to external APIs: - AI Screen OCR & Transcription: Sends selected image regions or voice notes to Google's Gemini API for processing. This requires you to provide your own Gemini API key in Settings. - Movie & Anime Data: Queries The Movie Database (TMDb) and Jikan (MyAnimeList) for media details and poster images. TMDb searches require your own TMDb API key. - Trailers: Embedded playback of YouTube trailers on media detail screens.

Screenshots

Cobalt screenshot 1
Cobalt screenshot 2
Cobalt screenshot 3

What’s new

- Added opt-in toggle for GitHub update checks (default off in FOSS).
- Fixed radial FAB menu to support direct tap selection.
- Decoupled Home screen feed from Search tab query.
- Completely removed sync/download background services from FOSS.
- Added custom User-Agent and guidance for anime search.
- Removed recurring backup notification dialog on note save.

How to install

  1. Download the APK from the button at the top of this page.
  2. Allow “Install unknown apps” for your browser or file manager only, not for every app.
  3. Open the downloaded file and confirm the installation.
  4. If installation fails with “App not installed,” remove an earlier build of the same app first. A signature conflict is the usual cause.

Data safety

  • Every file is checked against its published SHA-256 before it is listed.
  • Files are scanned for malware on every update.
  • The permissions each app requests are listed on its own page.
  • Read the full safety policy for how we test, flag, and delist files.

Frequently asked questions

What is Cobalt?
Universal offline-first note capture and personal knowledge archive
Who develops Cobalt?
Cobalt is developed by Hanan Bhatti.
Which Android version does Cobalt require?
Cobalt requires Android API 24 or later.
What is the current version of Cobalt?
The synchronized F-Droid version is 2.1.2.
Which license does Cobalt use?
The signed F-Droid metadata lists AGPL-3.0-or-later.
Where is the source code for Cobalt?
https://github.com/hanan-bhatti/cobalt

Comments

Recent approved comments · sorted by newest

Verification code
Be specific and keep it about the app. No links. Comments are reviewed before publication. Device and Android details are recorded automatically. Privacy policy.

Loading recent comments...

View all comments