Comparison

MarginNote 4 vs Calflow

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

Head to head
About

MarginNote 4

This app integrates reading, note-taking, mind mapping, and flashcards into a unified study environment. It supports active learning with features like study sets, book compilation, and dual-article views. Enhance your understanding with visual learning tools and AI-powered content extraction for long-term memory retention.

Highlights
  • Integrated reading, note-taking, mind mapping, and flashcards
  • Quick Extend Note and Handwriting Layers for annotation
  • Study Set for organizing PDFs, EPUBs, videos, and audio
  • Mind Map and Concept Diagram for visual learning
  • AI Content Detection for formula and chart extraction
  • FSRS spaced-repetition algorithm for reviews
  • iCloud sync across Apple devices
Features
Read full description

MarginNote is the PDF study tool for deep readers. One excerpt is a PDF highlight, a mind map node, and a flashcard — one capture, three places. This is the Card Axis architecture, so you stop ferrying content between a PDF reader, a notes app, and a flashcard tool. A decade of iteration. 188K+ App Store ratings. 【Four Featured Mechanics】 ▸ Card Axis — One excerpt, three renders. Document highlight, mind map node, and flashcard are the same card seen from three angles. ▸ Title Link — Old notes auto-surface in new documents. When a familiar concept appears in what you're reading, your past annotation lights up on the page. ▸ Extended Note — Long-press anywhere on a PDF to open writing space. No anchored text required; three display modes (inline / margin / collapsed). ▸ Immersive Mode (4.4) — Three-state toggle: Read / Write / Recall. UI folds away. Recall blurs excerpts with Gaussian blur — tap to reveal only after you've actually recalled. 【AI Capabilities (introduced in 4.2)】 AI book breakdown · AI OCR templates · AI translation · AI Q&A · AI flashcard generation Our stance is AI as assistant, not replacement — every suggestion can be saved as your own thinking node, never thinking for you. 【Apple Intelligence (iOS 26+)】 Recall Mode hints can run on-device via Apple Intelligence — pick "Apple AI" or "cloud LLM" in Settings. With Apple AI selected, three tiers of help — Neighbor Coordinate · Reasoning Prompt · Key Distinction — are generated by Apple Foundation Models right on your device: no network calls, no AI credits used, your notes never leave your device. Even if you've selected cloud LLM, going offline auto-falls back to Apple Intelligence (provided your device supports it) — so libraries, planes, and exam-day silent rooms never break your hint loop. 【Full Workflow】 Fast OCR · Study Sets (PDF / EPUB / video / audio) · direct read from Zotero / cloud drives / USB · 10 mind map styles · book recomposition · dual-document compare · concept maps · handwriting layers 【FSRS Spaced Repetition】 Built on the open-spaced-repetition project's algorithm (paper accepted by ACM SIGKDD; Anki has used FSRS as its default scheduler since v23.10). Push short-term memory into long-term. 【Built For】 Anyone re-reading a single document until it sticks — med school (USMLE / MCAT) · law school (LSAT / bar exam) · grad prep (GRE / GMAT / CFA) · researchers · language learners (IELTS / TOEFL) · serious readers. 【All Apple Platforms】 iPhone + iPad + Mac under one Apple ID. iCloud syncs Study Sets, notes, and review progress. Native Apple Pencil support on iPad. — Questions? Email service@marginnote.com Terms: https://dist.marginnote.com/MarginNote_Terms_and_Conditions.pdf Privacy: https://dist.marginnote.com/MarginNote_Privacy_Policy.pdf

About

Calflow

This app integrates with your existing iOS Reminders and Calendars to help you track how you spend your time. It offers features for daily planning, time tracking, and goal setting, providing insights into your productivity within the Apple ecosystem.

Highlights
  • 2-way sync with iOS Reminders & Calendar
  • Time tracking for reminders and events
  • Time distribution insights
  • Powerful tag system for filtering
  • Goal and habit tracking
  • Apple Health and app usage sync
Features
Read full description

If you’re using Apple Reminders and iOS Calendar/ Google Calendar in your workflow, and you wonder how you spend your time, tasks, daily activities, etc, it’s for you. Calflow is a powerful time-tracking planner based on iOS Reminders & Calendar, helping you keep track of your day and stay productive within the Apple ecosystem. Daily & Weekly Planner ◆ 2-way sync with iOS Reminders & Calendar (Free) ◆ Use Spaces to separate personal and work tasks, helping you declutter your schedule and stay focused Streamline Time-tracking into your Apple Workflow ◆ Track how much time you spend on your Reminders & events: - Reminders: Auto-populate time entries in Apple Calendar - Events: Auto-update your planned event details in Apple Calendar Apple Calendar Time Insights ◆ Also supports Google Calendar ◆ Track your time distribution across day/week/month/year Powerful Tag System ◆ Create smart tags to filter your calendar event entries, and learn about their activity across day/week/month/year ◆ Create groups to analyze time from multiple perspectives Goals, Habits Tracking ◆ Track goals, habits based on your iOS Reminders & Calendars to help ensure your time align with your goals Track anything and sync them to iOS Calendar ◆ Apple Health sync (mindful minutes, sleep time, workout time) ◆ App usage time tracking (via Shortcuts) ◆ Daily activities (via tracker widgets) Need help or have ideas to share? We’re always here: contact@calflow.app Terms of Use(EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://calflow.app/privacypolicy/

Screenshots

MarginNote 44 screens
Calflow4 screens

Verdict

The call

The clearest difference is review sentiment: Calflow at 88% against MarginNote 4's 59%. Calflow also leads on rating (4.9 vs 4.5). MarginNote 4's advantage is ratings volume (716 vs 121). On price, update cadence, ads and in-app purchases 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. MarginNote 4 sells 12 in-app purchases, starting at $1.99 per month and Calflow sells 3 in-app purchases, starting at $3.99 per month. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

Calflow holds the better App Store score, 4.9 against 4.5. That said, the two scores are not equally well evidenced: MarginNote 4 has 716 ratings behind it against 121, so its average is the more settled of the two. Written reviews point the same way: 59% of MarginNote 4's written reviews are positive against 88% of Calflow's.

UpkeepUpdate frequency

MarginNote 4 ships an update every 3 weeks, Calflow every 10 days. The most recent releases landed on September 22, 2026 and September 21, 2026 respectively.

Scorecard3 real differences · 7 level
MarginNote 4 versus Calflow: the parameters behind the verdict, then further details
ParameterMarginNote 4Calflow
PriceFreeFree
Rating4.5 (716 ratings)4.9 (121 ratings) — better
Positive reviews58.8% of reviews88.0% of reviews — better
Number of ratings716 — better121
Update frequencyEvery 3 weeksEvery 10 days — better
AdsNoNo
In-app purchasesYesYes
MonetizationFree with in-app purchasesFree with in-app purchases
DevicesiPhone, iPad, MaciPhone, iPad, Mac, Apple Watch — better
Requires iOS17.017.0
Further details — not scored
Size330 MB181 MB
Age rating4+4+
DeveloperBeijing Yunsi Software Technology Co., LtdKyovan Ltd.

Customer experience

MarginNote 4

All ratings716 ratings
Positive86.3%
Neutral3.6%
Negative10.1%
Written reviews563 reviews
Positive58.8%
Neutral15.3%
Negative25.9%

Calflow

All ratings121 ratings
Positive98.3%
Neutral0.8%
Negative0.8%
Written reviews92 reviews
Positive88.0%
Neutral5.4%
Negative6.5%

User reviews

MarginNote 4

From 716 App Store ratings

What we love

  • 🚀 Powerful features
  • 📚 Great for academic/research use
  • 👍 Useful note-taking and organization
  • 🖊️ Improved handwriting and annotation

Room to improve

  • 🐛 Buggy and crashes frequently
  • 🕰️ Slow and laggy sync between devices
  • 🤯 Steep learning curve, poor documentation
  • 💰 Expensive upgrade from previous version

Calflow

From 121 App Store ratings

What we love

  • ⏱️ Excellent time tracking with automatic logging
  • 📱 Seamless cross-device synchronization (iPhone, iPad, Mac, Apple Watch)
  • 📅 Perfect integration with Apple Calendar and Reminders
  • 🎯 Comprehensive goal-setting and insights features
  • 🧩 Simple, intuitive user interface with low friction

Room to improve

  • 🐛 Timer synchronization issues across devices
  • 🐛 Confusing insights calculation (double-counting existing calendar events)
  • 🐛 Apple Watch complications not fully functional
  • 🌙 No dark mode support
  • 📱 iPad lacks some features available on iPhone

Bugs and requests

MarginNote 4

Reported bugs

3 issues
  • Disappearing annotations when using extend function
  • Inability to restore accidentally deleted mind maps
  • Inconsistent behavior with PDF file management

Requested features

4 requests
  • Improved iCloud/cloud sync reliability
  • More intuitive and user-friendly interface
  • Better support for external document libraries
  • Ability to disable auto-excerpt selection

Calflow

Reported bugs

11 issues
  • Timer doesn't sync across devices (iPhone to iPad/Mac)
  • Live Activity not showing on iPad when timer active
  • Apple Watch timers not accessible on other devices
  • Widget display showing only black and white screen
  • Insights double-counting time on existing calendar events
Show 6 more
  • Goals feature sometimes fails to record correctly
  • iPad reminders list not syncing with iPhone
  • Timer in notification center and widget not syncing
  • iPad doesn't show timer notifications in notification center
  • Apple Watch connectivity issues after paid subscription activation
  • Mac and iPad timer not showing when started on iPhone

Requested features

27 requests
  • Dark mode support
  • Mac menu bar timer widget
  • Multiple simultaneous timers on iPhone
  • Larger font size options
  • Ability to copy and paste calendar events
Show 22 more
  • Custom goal cadences (not just daily/weekly/monthly)
  • Daily focus note area (like weekly focus)
  • Hashtag support in notes for better app integration
  • Apple Watch complications
  • Faster widget refresh rates
  • Drag and drop support for weekly plans
  • Collaboration/sharing features
  • Data export to CSV/Excel format
  • URL field for events and tasks
  • Callback URL support
  • Notification/reminder alerts for events
  • Milestone and skill tree features
  • Import data from other time tracking apps
  • Japanese language support
  • Custom day start time for analytics
  • Notebook/note-taking integration
  • Customizable todo background colors
  • Reminders list and tags binding
  • Mac automation scheduling
  • Website usage tracking on Mac
  • Ambient sounds and tick sounds for focus mode
  • Collaborative task management

In-app purchases

12 purchases

MarginNote 4

Subscriptions5
  • Subscription to MAX (Monthly)7 Days trial$1.991 Month
  • Subscription to MAX (3 months)7 Days trial$4.993 Months
  • Subscription to MAX (6 months)7 Days trial$7.996 Months
Show 2 more
  • Subscription to MAX (Annually)1 Month trial$12.991 Year
  • MarginNote Max Annual1 Month trial$16.991 Year
One-time7
  • 14 days Free Trial2 variantsFree
  • Upgrade to PRO from MN3(iOS)$4.99
  • Unlock PRO Forever (New)$12.99
Show 4 more
  • Upgrade to MAX from MN3(macOS)$19.99
  • Unlock MAX based on PRO$39.99
  • Unlock MAX based on PRO (New)$40.00
  • Unlock MAX Forever (New)$51.99
3 purchases

Calflow

Subscriptions2
  • Monthly plan$3.991 Month
  • Annual plan7 Days trial$12.991 Year
One-time1
  • One-time purchase$37.99

Questions

Is MarginNote 4 free?
MarginNote 4 is free to download, with in-app purchases available.
Is Calflow free?
Calflow is free to download, with in-app purchases available.
Which has better reviews, MarginNote 4 or Calflow?
Calflow is rated higher. MarginNote 4 averages 4.5 out of 5 from 716 ratings, while Calflow averages 4.9 from 121 ratings.
Do MarginNote 4 or Calflow have ads?
Neither MarginNote 4 nor Calflow shows ads.
Which is updated more often, MarginNote 4 or Calflow?
MarginNote 4 ships an update every 3 weeks, and Calflow every 10 days. Most recently, MarginNote 4 was updated on September 22, 2026 and Calflow on September 21, 2026.

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