Comparison

PDF Expert vs Slipster

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

Head to head
About

PDF Expert

This app allows you to edit, annotate, fill out forms, and convert PDF documents. It offers AI-powered summarization and analysis, along with tools to merge, sign, and protect your files. Work seamlessly across Apple devices with a user-friendly interface.

Highlights
  • Edit PDF text and images
  • Annotate and highlight PDFs
  • Fill out PDF forms
  • Convert files to and from PDF
  • AI-powered summarization and analysis
  • Merge and combine PDF files
  • Sign documents with e-signatures
Features
Read full description

PDF Expert is a fast and easy PDF app to read, annotate, fill and sign PDF forms, convert files to PDF, and merge, split or compress documents – all in one intuitive app for iPhone, iPad, Mac & Vision Pro. Read PDF files with comfort, highlight and mark up text, fill out forms, sign contracts, create and convert PDFs, and summarize long documents in seconds with AI-powered tools. Unlock unlimited possibilities with PDF Expert Premium and work across all your Apple devices. "PDF Expert is one of my must-have iPad apps and a desktop-class PDF reader." – MacStories "The best app for managing, editing, and reading PDFs on your iPad." – The Sweet Setup ▶ WITH PDF EXPERT, YOU CAN: READ PDFs - PDF reader with Day, Night, and Sepia modes for comfortable reading anytime - Scroll PDFs vertically or horizontally and search text in any document - Open and view PDF files from email, web, Files, or any app via the Share menu - Read PDFs out loud with Text to Speech ANNOTATE AND MARK UP PDFs - Highlight, underline, and strike through text in your PDFs - Mark up documents with pen, shapes, text, notes, and comments - Add stamps such as Approved or Confidential - Record your voice and add audio notes to PDFs FILL AND SIGN PDF FORMS - Fill out PDF forms with text fields, checkboxes, and radio buttons - Sign PDF documents in seconds – draw your signature or add it from an image - Save your signature to sign contracts, agreements, invoices, and applications faster - Fill, sign, and send forms right from your iPhone – no printing or scanning needed - Supports all major form formats, including AcroForms and static XFA forms ***PREMIUM FEATURES*** EDIT PDFs - Edit text directly in a PDF – just as you would in a Word document - Add, replace, and resize images in your PDFs - Add links to other pages or websites - Add outlines to navigate large PDFs CREATE AND CONVERT PDFs - Create PDFs from Word files, images, and other documents - Convert Word to PDF, JPG to PDF, and PNG to PDF in seconds - Convert PDF to Word, Excel, PowerPoint, JPG, PNG, and TXT MERGE, SPLIT AND ORGANIZE PDFs - Merge and combine multiple PDF files into one - Split PDFs and extract pages into a new file - Add, delete, rotate, and reorder pages with thumbnail preview COMPRESS PDFs - Compress PDFs to reduce file size for email and sharing - Shrink large PDF files to save space on your device SUMMARIZE PDFs WITH AI – PDF COPILOT - List Main Points – get key takeaways from any PDF - Summarize – get concise summaries of entire PDFs or annotations - Ask Anything – find details with AI answers and references - Explain – get instant explanations of words or phrases PROTECT YOUR FILES - Password-protect PDF Expert - Redact – permanently black out sensitive information WORK WITH SCANNED DOCUMENTS - Open scanned PDFs to fill out, sign, annotate, and share CONSTRUCTION TOOLS - Scale and measure drawings with the Measure tab - Polygon, polyline, and redline tools MORE FEATURES - Customizable toolbar - Presentation Mode - Print and share PDFs via email or cloud ONE ACCOUNT FOR ALL YOUR APPLE DEVICES One Premium subscription covers PDF Expert on iPhone, iPad, and Mac – no need to buy versions separately. Read more about our terms and conditions here: https://pdfexpert.com/privacy https://pdfexpert.com/terms Don’t hesitate to reach out to us at http://readdle.com/contact

About

Slipster

Features
Read full description

Slipster turns your to-do list into 15-minute tiles you can actually schedule - capture a task, size it, and either drop it onto your calendar or leave it in the list for later. CAPTURE FAST, SCHEDULE WHEN YOU'RE READY Add a task in seconds. Every task is sized in 15-minute units (1x-8x, so up to 2 hours) - small enough to actually start, not another vague "someday" item. Leave it in the list, or schedule it straight onto your day. YOUR OWN CALENDAR, NOT A TAKEOVER Schedule a task and Slipster creates its own "Slipster" calendar right on your device - no Google sign-in required, just one permission tap. It sits alongside your existing calendars, never mixed into them. It's two-way: move or rename the event in Calendar and Slipster picks up the change automatically. The list is always the source of truth - putting a task on the calendar is a loan, not a move. FOUR WAYS TO SEE YOUR DAY List, Day, Agenda, and Week views, plus categories (Home, Work, Shopping, and your own) so you can filter down to just what's relevant right now. RECURRING TASKS THAT DON'T MAKE YOU RE-TYPE THEM Set a task up once as a template - fixed day or floating to the next open slot - and stop retyping "bins out" or "water the plants" every single week. THE GAP-FILLER Slipster checks your other calendars' free/busy time and surfaces tasks that actually fit the gap you have right now - instead of leaving you to eyeball your calendar and guess. SLIPSTER PRO Everything above is free, forever - it's never getting paywalled retroactively. Slipster Pro is an optional subscription that adds sync across all your devices, so your list and schedule stay in step everywhere you use Slipster. No ads, no streaks, no guilt-trip notifications - just an honest way to get from "I should do that sometime" to it actually being on your calendar. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Screenshots

PDF Expert4 screens
Slipster4 screens

Verdict

The call

The clearest difference is update cadence: Slipster at daily against PDF Expert's fortnightly. PDF Expert's advantage is chart position (#67 vs unranked). On price, ads, in-app purchases 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. PDF Expert sells 10 in-app purchases, starting at $9.99 per month and Slipster sells 2 in-app purchases, starting at $2.99 per month. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

PDF Expert ships an update fortnightly, Slipster daily. The most recent releases landed on October 20, 2026 and October 5, 2026 respectively.

Scorecard2 real differences · 9 level
PDF Expert versus Slipster: the parameters behind the verdict, then further details
ParameterPDF ExpertSlipster
PriceFreeFree
Rating4.7 (216K ratings) — better—
Positive reviews45.4% of reviews—
Number of ratings216K — better—
Update frequencyFortnightlyDaily — better
AdsNoNo
In-app purchasesYesYes
MonetizationFree with in-app purchases—
Best chart rank#67 — better—
DevicesiPhone, iPadiPhone, iPad
Requires iOS16.0 — better17.0
Further details — not scored
Size295 MB29 MB
Age rating4+4+
DeveloperReaddle Technologies LimitedDCB Productions

Bugs and requests

PDF Expert

Reported bugs

4 issues
  • Corrupted PDFs after editing
  • Sync issues with cloud storage providers
  • Unexpected loss of annotations and edits
  • Unreliable performance on older iPad models

Requested features

5 requests
  • Improved palm rejection for Apple Pencil
  • Customizable toolbar and annotation presets
  • Better integration with other productivity apps
  • More flexible file management and organization
  • Ability to create fillable PDF forms

Slipster

Not enough reviews yet to summarise bugs or requests.

In-app purchases

10 purchases

PDF Expert

Subscriptions9
  • PDF Expert Premium Trial7 Days trial$9.991 Month
  • PDF Expert Premium No Trial$9.991 Month
  • PDF Expert for Education7 Days trial$39.991 Year
Show 6 more
  • PDF Expert Premium7 Days trial3 variants$49.991 Year
  • PDF Expert Premium New7 Days trial$49.991 Year
  • PDF Expert Premium Existing7 Days trial$49.991 Year
  • PDF Expert – Premium Editing1 Year trial$49.991 Year
  • PDF Expert Mac & iOS Pro7 Days trial$79.991 Year
  • PDF Expert Mac & iOS7 Days trial$79.991 Year
One-time1
  • PDF Expert Basic$9.99
2 purchases

Slipster

Subscriptions2
  • Slipster Pro Monthly$2.991 Month
  • Cross Device Sync - Yearly$29.991 Year

Questions

Is PDF Expert free?
PDF Expert is free to download, with in-app purchases available.
Is Slipster free?
Slipster is free to download, with in-app purchases available.
Do PDF Expert or Slipster have ads?
Neither PDF Expert nor Slipster shows ads.
Which is updated more often, PDF Expert or Slipster?
PDF Expert ships an update fortnightly, and Slipster daily. Most recently, PDF Expert was updated on October 20, 2026 and Slipster on October 5, 2026.

Other comparisons