Comparison

SIGMA vs PDF Converter

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

Head to head
About

SIGMA

Features
Read full description

Not: Bu uygulama yalnızca stok takibi ve öğrenme amaçlı geliştirilmiş bir projedir.

About

PDF Converter

Effortlessly transform paper documents into digital files with scanning, text recognition, and editing tools. Ideal for students, professionals, and everyday users needing to organize and manage documents.

Highlights
  • Photo scanning to digital files
  • OCR text recognition and copying
  • Import and view local PDFs
  • Page management (delete, rearrange)
  • Highlighting and annotation tools
  • Intuitive user interface
Features
Read full description

Still struggling to convert paper documents to digital files? Frustrated by the lack of reliable PDF editing tools? Your go-to PDF processing assistant—PDF Converter - OCR Reader—is here! Integrating scanning, recognition, conversion, and reading, it effortlessly solves document challenges in your studies, work, and daily life!   Suitable for all users: Not just for office work, but tailored to every need.   Students: Scan textbooks and notes, convert courseware, and highlight key knowledge points;   Professionals: Process contracts, scan meeting minutes, and convert business materials;   Everyday users: Archive receipts and invoices, scan certificate copies, and organize personal documents.   Comprehensive core features: Easily handle the entire document workflow.   Photo Scanning: Scan receipts, notes, courseware, certificates, and more! Manually activate the flash to adapt to low-light environments—one quick snap transforms paper documents into clear digital files.   OCR Text Recognition: Accurately extracts text from scanned documents, supporting one-click copying. No more manual typing—save time and effort!   PDF Import: Instantly access local PDFs on your device for direct viewing and quick import. No need to switch apps; select and edit seamlessly.   PDF Page Management: Delete unnecessary pages with one click! Rearrange page order freely to organize your document structure and keep files neat.   Highlighting & Annotation: Instant access to highlighting and freehand annotation tools! Mark important content easily, lock in key information, and streamline study notes or work annotations.   Intuitive Interface: Boasting an easy-to-understand design with a clear function layout. No extra learning is required—master all operations effortlessly, even for beginners.   Unlock a convenient, practical multi-scenario PDF processing experience with PDF Converter - OCR Reader! - Ad-Free Premium - Completely removes all ads, pop-ups, and promotional content. Clean interface, smooth operation, and no distractions. Subscription Notes 1. After subscription confirmation, payment will be processed through your iTunes account. 2. Subscriptions will automatically renew. To disable automatic renewal, you must do so at least 24 hours before the end of the current subscription period in your account settings. 3. After purchasing your subscription, you can manage your subscription status and cancel automatic renewal in your account settings. For details, please refer to the following links: Privacy Policy: https://pdfconverterocrreader.com/privacy.html Terms of Use: https://pdfconverterocrreader.com/terms.html Subscription Terms: https://pdfconverterocrreader.com/subscription_terms.html

Screenshots

SIGMA2 screens
PDF Converter4 screens

Verdict

The call

The clearest difference is in-app purchases: SIGMA at none against PDF Converter's 2. SIGMA also leads on ads (none vs shown) and iOS requirement (13.0 vs 15.6). On price, update cadence 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 Converter sells 2 in-app purchases, starting at $5.99 per 7 days. SIGMA asks for nothing beyond the download.

UpkeepUpdate frequency

SIGMA ships an update monthly, PDF Converter every 2 weeks. The most recent releases landed on September 5, 2026 and September 21, 2026 respectively.

Scorecard3 real differences · 7 level
SIGMA versus PDF Converter: the parameters behind the verdict, then further details
ParameterSIGMAPDF Converter
PriceFreeFree
Rating—4.7 (22 ratings) — better
Positive reviews—18.2% of reviews
Number of ratings—22 — better
Update frequencyMonthlyEvery 2 weeks — better
AdsNo — betterYes
In-app purchasesNo — betterYes
Monetization—Free with in-app purchases
DevicesiPhone, iPad, iPod — betteriPhone, iPod
Requires iOS13.0 — better15.6
Further details — not scored
Size25 MB93 MB
Age rating4+4+
DeveloperTurker KAYALIOLUHitek Limited

In-app purchases

None

SIGMA

No in-app purchases

2 purchases

PDF Converter

Subscriptions2
  • PDF Converter Ad-Free$5.997 Days
  • PDF Converter Ad-Free$29.991 Year

Questions

Is SIGMA free?
SIGMA is free to download, with no in-app purchases.
Is PDF Converter free?
PDF Converter is free to download, with in-app purchases available.
Do SIGMA or PDF Converter have ads?
PDF Converter shows ads; SIGMA does not.
Which is updated more often, SIGMA or PDF Converter?
SIGMA ships an update monthly, and PDF Converter every 2 weeks. Most recently, SIGMA was updated on September 5, 2026 and PDF Converter on September 21, 2026.

Other comparisons