Comparison

PDF Viewer by Nutrient vs Ukonik

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

Head to head
About

PDF Viewer by Nutrient

Easily view, search, and annotate PDF documents on your iPhone and iPad. Access files from cloud services, fill out forms, add signatures, and organize your documents. Advanced features are available through a subscription.

Highlights
  • View, search, and annotate PDFs
  • Cloud service integration
  • Fill out forms and add signatures
  • Create and edit PDF pages
  • Password protection
  • Night mode and text-to-speech
Features
Read full description

PDF Viewer is a fast and beautiful app, allowing you to view, search, and annotate PDF documents with ease on your iPhone and iPad. Access your files from iCloud, Dropbox, Box, OneDrive, Google Drive or any other cloud solution via Apple's familiar Document Browser interface. +++ Listed as “Productivity lifesaver” on the App Store +++ "A streamlined interface packed with powerful features - it’s like having a desktop-quality PDF toolkit wherever we go" – App Store Editor Notes “I'm impressed by how the folks at PSPDFKit have been able to fine-tune the document browser to the app's needs.” – MacStories.net "If you want a PDF viewer that is designed for reading PDF books, this is it." – App Review VIEW DOCUMENTS ON THE GO • Easily import a PDF from your favorite cloud service provider, email, or directly off a website. • Supports Open In Place, Drag & Drop and features the familiar Apple Document Browser interface from the Files app. • Search for the exact text you are looking for within the document. • Double tap on the screen to Smart Zoom directly to the text you want to read. • Annotate images (JPEG, PNG) non-destructive, just like PDF documents. (PRO) ANNOTATE WITH EASE • While reviewing a document, use your finger or Apple Pencil to highlight and markup text. • Leave comments by adding a note, text, or drawing directly on the PDF. • Add images or audio. • Reply to notes. (PRO) SIGN DOCUMENTS ANYWHERE • Add your signature to any document using your finger or Apple Pencil. • Move and resize your signature as needed. • Flatten a document to ensure the signature doesn’t change. CREATE AND EDIT PDFs • Create new documents from existing documents by moving, rotating, deleting, or adding new pages. • Combine multiple documents into a single one. (PRO) • Add bookmarks to easily return to certain pages in large documents. FILL OUT FORMS • Quickly fill out PDF Forms by adding text to the fields. • Flatten and secure the form once you’re done to ensure the document doesn’t change. • Add a signature to any Form. STORE, ORGANIZE AND SHARE • Store documents, create folders and organize your documents. • Share documents by printing, emailing or saving your edits back any cloud service. PASSWORD PROTECT DOCUMENTS • Read document metadata, title and keywords. • Protect documents with user and owner passwords and limit permissions. (PRO) AND SO MUCH MORE • Conveniently switch to night mode when viewing your documents at night. • Present on external screens without the distraction of toolbars. (PRO) • Have the text from a PDF read out loud to you with text-to-speech. • PDF Viewer remembers where you were down to the page/position where you left off - even across devices. PRICING PDF Viewer comes with a large feature set, completely free. Some advanced features require the purchase of PDF Viewer Pro, available as a subscription. We offer 3-monthly and yearly subscription plans. There’s also a fully functional 7-day trial, so you can test PDF Viewer Pro (including document merging and password editing) before you commit. All plans unlock the app on iPhone and iPad. TRUSTED BY COMPANIES YOU KNOW PDF Viewer is built on top of and powered by PSPDFKit, the same PDF engine trusted around the world by companies like Dropbox, Box, IBM, Atlassian, SAP, and Lufthansa. BE PART OF THE PDF VIEWER COMMUNITY pdfviewer.io twitter.com/pdfviewerapp LEGAL Duration and price of each subscription are displayed in PDF Viewers’ storefront, updated at the time of purchase. Payment will be charged to iTunes account at confirmation of purchase. Subscriptions automatically renew unless auto-renew is turned off no later than 24 hours before the end of the current period. Subscriptions and auto-renewal can be managed/turned off in the iTunes account settings. Any unused portion of a free trial period is forfeited as soon as a subscription is purchased. Terms of Use: https://pdfviewer.io/terms Privacy Policy: https://pdfviewer.io/privacy

About

Ukonik

This app analyzes your calendar and body recovery data to provide a daily performance load score. It helps you understand when to push and when to rest, offering insights and tools to optimize your schedule and well-being.

Highlights
  • Daily performance load score
  • Calendar and body recovery integration
  • Push/recover recommendations
  • Focus time protection
  • Weekly AI insights
  • Calendar event analysis
Read full description

Ukonik turns your Google Calendar or Outlook Calendar into a daily performance load score, adds how your body actually recovered, and shows you when to push and when to recover. HOW IT WORKS Connect your calendar: link Google Calendar or Outlook in one tap. No manual entry. Get your daily score: every meeting is scored for its load and rolled into one number with a quick daily check-in (Fresh, Steady, Taxed, Drained, Spent). Home shows how much room today has left. Add your body: connect Apple Health to bring in sleep, HRV and resting heart rate. Act on it: protect focus time, take a Nervous System Reset, and rebalance your week before load piles up. WHAT'S INCLUDED Daily load score: points on every event show exactly what drives the number, with a 5-day forecast of heavy days. Load readiness: how much load your body is ready for today, from last night's recovery against your calendar. Body readiness: Recovered, Typical or Under-recovered, from your sleep, HRV and resting heart rate. Priorities: choose what matters (Deep work, One-on-ones and 11 more domains), set weekly targets, and see where your time actually goes. Focus blocks: start a focus session for a priority and Ukonik adds it to your calendar, or link an iOS Focus mode with the Focus Filter. Ukonik interview: a two-minute review of your week that suggests focus blocks and priority changes. Calendar insights: 7, 30 and 90-day load trends, priority cadence and a weekly reflection. Each day shows how its score adds up, including daily caps. Your patterns: how heavy days show up in your recovery, from your own data. Nervous System Reset: a guided four-count reset that offsets your load score, with Pause. Alerts and nudges: spot sustained high load before it piles up, choose how and when each notification reaches you, and set Quiet hours so pushes wait until you're ready. Themes: five color themes, light or dark, on every plan. FREE, NO CARD REQUIRED Daily load score & check-in · 5-day forecast · 2 priorities and your own load budget · Ukonik interview once a week · 1 Google Calendar · Edit event title & time · Nervous System Reset · Schedule a 15-minute break · Critical Spike, Sustained High, and Recovery Due alerts · Late finish, back-to-back, low load, holiday, and seasonal nudges · Themes · Quiet hours PULSE: YOUR BODY IN THE PICTURE Everything in Free · Apple Health: sleep, HRV, resting heart rate, and workouts added to your calendar · Body readiness and Load readiness · Unlimited priorities with weekly targets and calendar insights · Focus blocks · iOS Focus Filter · Ukonik interview any time · Weekly AI insight · Your patterns · 2 Google Calendars · Add calendar events · Color your calendar by priority SIGNAL: AN AGENT THAT BOOKS THE TIME Everything in Pulse · Up to 3 calendars (Google + Outlook) · Delete calendar events · AI scheduling agent that defends focus time, schedules breaks, and protects recovery (every change is proposed, never automatic: you approve or decline) · Ukonik interview books focus blocks for you · Weekly planning session · Monthly AI insight and midweek feedback · AI coaching on Home · Rapid Escalation, Above Baseline, and Quarter-End alerts · No lunch gap, high load, and missing recurring nudges YOUR DATA STAYS YOURS Ukonik reads what it needs to score your day: event times, durations, attendee counts and titles. Titles are shown only to you, never shared with other users or used to train AI models, and sent to our AI provider only for two optional features you turn on. Apple Health data is optional, granted per data type, never sold or used for advertising, and you can purge it at any time. Ukonik never creates, edits, or deletes a calendar event without your confirmation. Ukonik is a performance tool, not a medical device, and doesn't provide medical advice, diagnosis, or treatment. Terms of Use: https://ukonik.com/terms Privacy Policy: https://ukonik.com/privacy

Screenshots

PDF Viewer by Nutrient4 screens
Ukonik4 screens

Verdict

The call

The clearest difference is rating: Ukonik at 5.0 against PDF Viewer by Nutrient's 4.6. Ukonik also leads on update cadence (every 10 days vs monthly). PDF Viewer by Nutrient's advantage is ratings volume (9.1K vs 1) and device support (4 vs 2). On price, ads, in-app purchases and monetization model 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. PDF Viewer by Nutrient sells 2 in-app purchases, starting at $6.99 per 3 months and Ukonik sells 2 in-app purchases, starting at $4.99 per month. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

Ukonik holds the better App Store score, 5.0 against 4.6. That said, the two scores are not equally well evidenced: PDF Viewer by Nutrient has 9.1K ratings behind it against 1, so its average is the more settled of the two.

UpkeepUpdate frequency

PDF Viewer by Nutrient ships an update monthly, Ukonik every 10 days. The most recent releases landed on November 10, 2026 and November 6, 2026 respectively.

Scorecard4 real differences · 6 level
PDF Viewer by Nutrient versus Ukonik: the parameters behind the verdict, then further details
ParameterPDF Viewer by NutrientUkonik
PriceFreeFree
Rating4.6 (9.1K ratings)5.0 (1 ratings) — better
Positive reviews73.2% of reviews—
Number of ratings9.1K — better1
Update frequencyMonthlyEvery 10 days — better
AdsNoNo
In-app purchasesYesYes
MonetizationFreemiumFreemium
DevicesiPhone, iPad, Mac, Vision Pro — betteriPhone, iPad
Requires iOS17.016.4 — better
Further details — not scored
Size111 MB54 MB
Age rating4+9+
DeveloperPSPDFKit GmbHWellkirk

Customer experience

PDF Viewer by Nutrient

All ratings9,112 ratings
Positive90.8%
Neutral3.7%
Negative5.4%
Written reviews1,095 reviews
Positive73.2%
Neutral9.8%
Negative17.1%

Ukonik

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

Bugs and requests

PDF Viewer by Nutrient

Reported bugs

4 issues
  • Annotations randomly disappearing or not saving
  • Incompatibility issues with certain PDF files
  • Scrolling and panning problems on large PDFs
  • Unexpected crashes after iOS updates

Requested features

5 requests
  • Add a rubber/eraser tool for annotations
  • Implement a side-by-side PDF view mode
  • Improve palm rejection and gesture support
  • Allow customization of toolbar and shortcuts
  • Provide better options for PDF file management

Ukonik

Not enough reviews yet to summarise bugs or requests.

In-app purchases

2 purchases

PDF Viewer by Nutrient

Subscriptions2
  • PDF Viewer Pro 3 Months7 Days trial$6.993 Months
  • PDF Viewer Pro Yearly7 Days trial$19.991 Year
2 purchases

Ukonik

Subscriptions2
  • Ukonik Pulse$4.991 Month
  • Ukonik Signal$9.991 Month

Questions

Is PDF Viewer by Nutrient free?
PDF Viewer by Nutrient is free to download, with in-app purchases available.
Is Ukonik free?
Ukonik is free to download, with in-app purchases available.
Which has better reviews, PDF Viewer by Nutrient or Ukonik?
Ukonik is rated higher. PDF Viewer by Nutrient averages 4.6 out of 5 from 9.1K ratings, while Ukonik averages 5.0 from 1 ratings.
Do PDF Viewer by Nutrient or Ukonik have ads?
Neither PDF Viewer by Nutrient nor Ukonik shows ads.
Which is updated more often, PDF Viewer by Nutrient or Ukonik?
PDF Viewer by Nutrient ships an update monthly, and Ukonik every 10 days. Most recently, PDF Viewer by Nutrient was updated on November 10, 2026 and Ukonik on November 6, 2026.

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