Comparison

pdf vs 아이두

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

Head to head
About

pdf

Manage and annotate PDF files on your iPad with fast page turning and intuitive finger-writing. Easily import, organize, and share your notes with friends. Offers a seamless reading and editing experience.

Highlights
  • Fast page turning and content scanning
  • Intuitive finger-writing with zoom-in
  • Easy PDF import via Dropbox, Email, or iTunes
  • Organized bookshelves with search
  • Variety of pens, highlighters, and text notes
  • Export annotated PDFs via email
Features
Read full description

Utilize pdf-notes to manage all the pdf files on your iPad. Fast display, quick page-turning even a thousand pages, useful finger-writing and email your notes to your friends. Differentiation-1. While turning pages of paperbooks fast, you can glance over the pages. While turning pages of pdf-notes fast, you can still run over the contents. Speedy page turning and scanning the contents with pdf-notes or paperbooks. Differentiation-2. There are many pdf readers allow you to annotate; but do you know which app allows you can write any notes in a second? If you are using pdf-notes, you may experience very fast and intuitive finger-writing like: zoom-in and note by double-tap or; writing with one finger, page-turning with two fingers, pen-changing with three fingers. - Easy importing PDF files through (DropBox, Email or Safari's) "Open In..." or iTunes - Categorized multiple bookshelves(booklists) with powerful search - Displaying pages as optimized size 1024x768 of iPad - Portrait and landscape view - Pinch zoom and crop page-margins - Fast loading and Speedy page-turning - Finger-writing with a variety of pens, highlighters and text notes - Easy "zoom-in and note" on a magnified screen by a double tap - One-step page-turning using 2 fingers on editing mode - One-step pen-changing or undo/redo using 3 fingers on editing mode - Exporting annotated PDF files to Email - External display and screen brightness controls - AirPrint and multi-tasking Misunderstandings about pdf-notes: - Not only pdf-notes but every app recently updated is removed from the open-in menu because iOS5 or formers currently show only 10 apps in open-in menu. - iPad/iphone Mail/iBooks can't display PDF annotations so that please open it in the other pdf apps. - please visit the support site for more information http://bit.ly/f6D31P Blog http://pdf-notes.com Email musebook@musebook.com Twitter http://twitter.com/musebook4u YouTube http://youtu.be/4AyRyFq9yxg NOTE: All content contained herein is subject to change without notice.

About

아이두

This app uses AI to help you manage your daily tasks and stay motivated with friends. It organizes your to-dos automatically, tracks your progress, and allows you to share your goals and achievements with others for mutual encouragement.

Highlights
  • AI-powered task parsing and organization
  • Social sharing of to-dos with friends
  • Progress tracking and achievement streaks
  • Customizable reminders and notifications
  • Color-coded task categorization
  • Weekly and monthly AI reports (Pro)
Features
Read full description

Managing your to-dos alone never really works, does it? Aido is a social to-do app that helps you finish what you set out to do every day — with the power of AI and friends. Just say the word and your tasks organize themselves, and with friends alongside you, staying consistent becomes easy. [ Smart To-Do Management, Powered by AI ] - Speak or type, and AI automatically parses the task, date, and time - Create recurring schedules with a single phrase like "workout every Mon/Wed/Fri" - AI analyzes your patterns and suggests recurring routines automatically (Pro) - Weekly and monthly AI reports break down your completion rate and patterns by category and day (Pro) [ Stay Motivated with Friends ] - Find friends by user tag (#) and see each other's to-dos in the feed - Give a nudge when someone's slacking off - Send cheers to friends who've finished all their tasks - Together, a three-day resolution becomes an everyday one [ See Your Growth at a Glance ] - Check your daily completion rate on the weekly and monthly calendar - Record your consistency with achievement streaks - Visualize your progress with AI weekly reports and plan next week's strategy (Pro) [ Clean Schedule Management ] - Organize tasks with color tags by category - Manage to-dos like events with date and time settings - Auto-generate weekly routines with recurring to-dos - Sort by priority with drag and drop - Choose what to share with public/private settings [ Reminders That Fit You ] - Start and end your day with morning and evening reminders - Get automatic alerts 60 and 10 minutes before a task begins - Customize reminder times freely (Pro) [ Make It Yours ] - Light / Dark / System themes - 6 premium cat-themed app icons [ Easy to Start ] - Social login with Kakao, Google, Naver, and Apple - Sign up with email, too Recommended for - Anyone who keeps putting tasks off - Anyone whose solo plans fizzle out in a few days - Anyone who wants to grow by motivating each other with friends - Anyone who wants to organize tasks quickly with AI - Anyone who wants to review their productivity every week Start with today's to-dos alongside Aido right now. [ Subscription Details ] Aido offers its core features for free. With an Aido Pro subscription, you can access the following premium features: - Unlimited AI usage - AI weekly and monthly reports - Automatic routine suggestions - Customizable reminder times - Premium app icons (6 cat themes) - Payment will be charged to your iTunes account at confirmation of purchase. - Your subscription automatically renews unless auto-renew is turned off at least 24 hours before the end of the current period. - You can manage your subscription in your device settings after purchase. Terms of Service: https://aido.kr/ko/terms Privacy Policy: https://aido.kr/ko/privacy [ Data Sources ] This service uses public data from the Public Data Portal (data.go.kr). - Korea Meteorological Administration: short-term forecasts, living weather index (UV) - AirKorea (Korea Environment Corporation): real-time air quality data (PM10, PM2.5) - Korea Astronomy and Space Science Institute: sunrise and sunset times

Screenshots

아이두4 screens

Verdict

The call

The clearest difference is price: 아이두 at Free against pdf's $9.99. 아이두 also leads on rating (5.0 vs 4.4) and update cadence (every 2 days vs every 2 weeks). pdf's advantage is in-app purchases (none vs 2) and ratings volume (27 vs 1). On ads, device support and iOS requirement 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

아이두 is free to download; pdf costs $9.99 up front. 아이두 sells 2 in-app purchases, starting at $2.99 per month. pdf asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

아이두 holds the better App Store score, 5.0 against 4.4. That said, the two scores are not equally well evidenced: pdf has 27 ratings behind it against 1, so its average is the more settled of the two.

UpkeepUpdate frequency

pdf ships an update every 2 weeks, 아이두 every 2 days. The most recent releases landed on October 9, 2026 and October 1, 2026 respectively.

Scorecard6 real differences · 4 level
pdf versus 아이두: the parameters behind the verdict, then further details
Parameterpdf아이두
Price$9.99Free — better
Rating4.4 (27 ratings)5.0 (1 ratings) — better
Positive reviews71.5% of reviews—
Number of ratings27 — better1
Update frequencyEvery 2 weeksEvery 2 days — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationPaidFreemium — better
DevicesiPadiPhone, iPad — better
Requires iOS16.0 — better16.4
Further details — not scored
Size138 MB107 MB
Age rating4+4+
DeveloperAMuseTec Co., Ltd.yongmin kim

Customer experience

pdf

All ratings27 ratings
Positive85.2%
Neutral7.4%
Negative7.4%
Written reviews288 reviews
Positive71.5%
Neutral9.7%
Negative18.8%

아이두

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

pdf

No in-app purchases

2 purchases

아이두

Subscriptions2
  • Aido Pro$2.991 Month
  • Aido Pro$19.991 Year

Questions

Is pdf free?
pdf costs $9.99, with no in-app purchases.
Is 아이두 free?
아이두 is free to download, with in-app purchases available.
Which has better reviews, pdf or 아이두?
아이두 is rated higher. pdf averages 4.4 out of 5 from 27 ratings, while 아이두 averages 5.0 from 1 ratings.
Do pdf or 아이두 have ads?
Neither pdf nor 아이두 shows ads.
Which is updated more often, pdf or 아이두?
pdf ships an update every 2 weeks, and 아이두 every 2 days. Most recently, pdf was updated on October 9, 2026 and 아이두 on October 1, 2026.

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