Comparison

Plainsight vs Cairn

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Plainsight

Features
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PlainSight: The Disguised Note Vault Keep your most sensitive notes completely invisible to everyone else. No obvious PIN pads. No suspicious lock screens. Just total privacy, hidden in plain sight. PlainSight looks and functions like a beautiful, minimal note-taking app on the surface—perfect for daily tasks, grocery lists, and quick thoughts. But underneath its calm interface holds a powerful secret. By typing your own custom secret command phrase directly into a standard note field, PlainSight instantly unlocks your hidden workspaces. To an outside observer or anyone browsing your phone, your private vaults don't even exist. HOW IT WORKS: THE SECRET KNOCK CREATE YOUR TRIGGER Choose absolutely any secret phrase or word like .banana, ..manage, or a custom string of text. TYPE TO REVEAL Type your secret phrase anywhere in the text field to instantly slide open your private workspaces. TOTAL PLAUSIBLE DENIABILITY PlainSight doesn't broadcast that you have something to hide. There are no "Incorrect Password" errors or biometric pop-ups to raise suspicion if you hand your phone to a friend, colleague, or family member. POWERFUL PRIVACY, MINIMALIST DESIGN WRITE WITH CLARITY Open instantly into a clean, distraction-free editor. No toolbars, no clutter—just a smooth, fast writing space that stays out of your way. ORGANIZE EFFORTLESSLY Group your sensitive data using lightweight tags and categories. Keep your personal journals, account numbers, business ideas, or travel itineraries meticulously structured. SECURE EMAIL RECOVERY Forget your secret word? Don't panic. You can securely reset your access via an encrypted recovery code sent to your email. Your notes remain completely local, encrypted, and yours—but you'll never be locked out. SECURE REAL-TIME COLLABORATION Need to share a shopping list with a partner or collaborate on a private project with a teammate? Turn any workspace into a shared space. PlainSight syncs instantly across devices in real time, giving you seamless multi-user collaboration without the bloat of heavy corporate productivity tools. FEATURES BUILT TO STAY INVISIBLE Fast writing tools and clean formatting Custom tags and categories Real-time multi-user collaboration Archive, delete, and restore controls Secure workspace management Smooth, instant cloud sync NO SUBSCRIPTIONS. NO SURPRISES. PlainSight is fully free for simple, personal note-taking. If you want advanced power—including multi-user shared workspaces, unlimited hidden spaces, and full real-time cloud sync across devices—unlock everything with a single, small, one-time upgrade. No monthly fees, ever. Protect your thoughts with absolute discretion. Download PlainSight and secure your notes today.

About

Cairn

Manage tasks and notes directly within your existing Markdown files. This app offers focused views, quick capture, and robust task management features, all while keeping your data private and locally stored. It integrates seamlessly with Obsidian and other file sync services.

Highlights
  • Native Markdown task and note management
  • Works with Obsidian vaults or any folder
  • Quick capture with date, tag, and priority parsing
  • Multiple task views (Today, Upcoming, Inbox, Pool)
  • Full support for sub-tasks and recurring tasks
  • Local reminders and Live Activity integration
  • Data stays local, no cloud sync required
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Cairn is a fast, native task and note companion that lives on top of the Markdown files you already own. Point it at your Obsidian vault — or any folder of Markdown notes — and your tasks and notes appear in clean, focused views. Everything you do in Cairn is written straight back to your files as plain text, in the Obsidian Tasks format. YOUR NOTES STAY YOURS • No account, no sign-up, no Cairn cloud database — your tasks live in your own files • Cairn does not send your notes or tasks to the developer • Careful, patch-based edits change only the content you touched, preserving the rest of your note • Works alongside Obsidian, iCloud Drive, Git, or any sync you already use CAPTURE, BROWSE, AND PLAN • Browse and edit Markdown notes directly in your vault • Quick capture into your daily note, with date, tag, and priority tokens parsed as you type • Choose where longer captures are saved • Today, Upcoming, Inbox, and Pool views, plus a global filter for folders, tags, dates, priority, and status • Full support for sub-tasks and task hierarchies • Recurring tasks in Obsidian Tasks format, with safe completion handling • Convert upcoming calendar events into tasks, or mirror your dated tasks into a calendar you choose (optional) STAY ON TRACK • Local reminders for due tasks — including sunrise-relative reminders computed entirely on your device • A Live Activity keeps today's progress on your Lock Screen and in the Dynamic Island • Home Screen widgets and a Control Center quick-capture control • Search across every task in your vault MADE FOR OBSIDIAN — NOT ONLY OBSIDIAN Cairn reads and writes the Obsidian Tasks plugin format (due, scheduled, start, and done dates, priorities, recurrence, tags), so your vault stays fully compatible with your desktop setup. Don't use Obsidian? Create a plain task folder in the Files app and Cairn works as a stand-alone Markdown to-do app. Cairn asks for access only to the folder you pick. Calendar access and location (used to compute local sunrise times) are optional and processed on your device. If you choose iCloud Drive or another Files or calendar provider, that provider's own sync and privacy terms apply.

Screenshots

Plainsight4 screens
Cairn4 screens

Verdict

The call

The clearest difference is in-app purchases: Cairn at none against Plainsight's 1. Cairn also leads on update cadence (every 6 days vs every 2 weeks). Plainsight's advantage is iOS requirement (15.0 vs 17.0). On price, ads and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Plainsight sells 1 one-off in-app purchase. Cairn asks for nothing beyond the download.

UpkeepUpdate frequency

Plainsight ships an update every 2 weeks, Cairn every 6 days. The most recent releases landed on September 29, 2026 and October 17, 2026 respectively.

Scorecard3 real differences · 7 level
Plainsight versus Cairn: the parameters behind the verdict, then further details
ParameterPlainsightCairn
PriceFreeFree
Rating—5.0 (1 ratings) — better
Positive reviews—100.0% of reviews
Number of ratings—1 — better
Update frequencyEvery 2 weeksEvery 6 days — better
AdsNoNo
In-app purchasesYesNo — better
Monetization—Free
DevicesiPhone, iPodiPhone, iPad
Requires iOS15.0 — better17.0
Further details — not scored
Size27 MB9 MB
Age rating4+4+
DeveloperKLEEM STUDIO, LLCYoung Hun JEONG

In-app purchases

1 purchases

Plainsight

One-time1
  • Plainsight - Private Notes$4.99
None

Cairn

No in-app purchases

Questions

Is Plainsight free?
Plainsight is free to download, with in-app purchases available.
Is Cairn free?
Cairn is free to download, with no in-app purchases.
Do Plainsight or Cairn have ads?
Neither Plainsight nor Cairn shows ads.
Which is updated more often, Plainsight or Cairn?
Plainsight ships an update every 2 weeks, and Cairn every 6 days. Most recently, Plainsight was updated on September 29, 2026 and Cairn on October 17, 2026.

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