Comparison

PDF Merger vs Simple Letter

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

Head to head
About

PDF Merger

Features
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PDF Merger 2.0 is the fastest, most private way to combine, split, compress, scan, OCR, and sign PDFs on iPhone and iPad — now with built-in AI Chat powered by Gemini. — NEW IN 2.0 — • AI Chat (Gemini 2.5 Flash-Lite) — Ask any PDF anything. Summaries, lookups, totals, translations. Opt-in, with no chat history stored on our servers. 5 free questions/week. • OCR (on-device) — Recognise text on scanned PDFs in 30+ languages. Searchable, copyable, exportable. • Page Extraction — Pull any page into its own PDF in one tap. • Page Numbering — Add numbers to every page with custom format & position. • E-Signature — Stamp a saved signature image with date. • Cover Page Bundler — Auto-generate a cover with title + table of contents. • Insert Blank Page — Perfect for chapter breaks. • 40+ Languages — Fully localized UI and App Store keywords. • iPad Polished — Sidebar layout, drag-and-drop, Apple Pencil ready. — CORE FEATURES — • Merge PDFs — Drag, drop, and reorder unlimited files into one PDF. • Split PDFs — Extract page ranges or single pages with one tap. • Compress PDFs — Shrink size up to 80% while preserving readability. • Rotate Pages — Fix sideways scans, per-page or in batch. • Add Watermark — Text or image, adjustable opacity and position. • Password Lock — AES-128 encrypted PDFs. • Document Scanner — Camera-to-PDF with auto-crop and perspective correction. • JPG to PDF — Photos to PDF with auto-cropping. • PDF to Images — Each page as JPG or PNG. • Apple Intelligence — Smart Summary + Auto-Rename, fully on-device. — PRIVACY-FIRST — • PDF processing stays 100% on your device. • AI Chat is opt-in. When enabled, only the text of the PDF you're asking about is sent to Gemini, cached for 1 hour, and never stored beyond that. • No tracking, no analytics, no advertising. • Files live in your private app sandbox; deleted when you delete them. — PRO TIER (optional) — Unlock unlimited merges, larger batches, watermark removal, password protection, document scanner, OCR, e-signature, AI Chat, Apple Intelligence Smart Summary, and every new feature with a single subscription or one-time Lifetime purchase. • Weekly — try Pro for less than a coffee • Yearly — save 70% • Lifetime — pay once, own forever Subscriptions auto-renew unless cancelled at least 24 hours before the renewal date. Payment is charged to your Apple ID. Manage in Settings → Apple ID → Subscriptions. — DESIGNED FOR iOS — • Built natively with SwiftUI + PDFKit for iOS 17+. • Optimized for iPhone, iPad, and Apple Pencil. • Full Dark Mode support. • Dynamic Type accessibility throughout. • VoiceOver labels on every interactive control. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://www.freeprivacypolicy.com/live/dca821a0-9b8b-48a6-9565-d1c64344a313

About

Simple Letter

Features
Read full description

Simple Letter helps you to create clean, well-formatted letters on iPhone, iPad and Apple Silicon Mac. Write personal or professional letters with a clear structure for sender, addressee, subject, greeting, main text, closing and signature. Customize fonts, font size, spacing, sender style, alignment and print margins, then print or export using the system print flow. Simple Letter also includes Apple Intelligence features on supported devices to help you generate draft text and improve existing letters. All processing happens locally on your device, helping to keep your data secure. Simple Letter Pro unlocks advanced tools for users who write letters regularly, including reusable templates, multiple sender profiles, multiple signatures, unlimited letter length and AI rewrite tools. Key Features: • Create formal letters with a simple, guided layout • Works on iPhone, iPad and Apple Silicon Mac • Customize sender style, sender alignment, fonts, font size, spacing and print margins • Print or export through the system print dialog • Save, reopen, search, sort and duplicate letters • Add a handwritten signature • Use Apple Intelligence on supported devices to generate and improve letter text • Keyboard shortcuts on iPad and Mac Simple Letter Pro: • Unlimited main-text length • Multiple sender profiles • Multiple saved signatures • Built-in starter templates for common letter scenarios • AI rewrite tools for tone changes and refinement • Rewrite in another language on supported devices

Screenshots

PDF Merger3 screens
Simple Letter4 screens

Verdict

The call

The clearest difference is update cadence: Simple Letter at every 2 weeks against PDF Merger's every 9 months. PDF Merger's advantage is iOS requirement (17.0 vs 26.0). On price, ads, in-app purchases and device support there is nothing between them.

Scored on Price Ā· Rating Ā· Positive reviews Ā· Number of ratings Ā· Update frequency Ā· Ads Ā· In-app purchases Ā· Monetization Ā· Best chart rank Ā· Devices Ā· Requires iOS

CostPrice Ā· In-app purchases Ā· Ads Ā· Monetization

Both are free to download. PDF Merger sells 3 in-app purchases, starting at $1.99 per 7 days and Simple Letter sells 3 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

PDF Merger ships an update every 9 months, Simple Letter every 2 weeks. The most recent releases landed on October 7, 2026 and October 23, 2026 respectively.

Scorecard2 real differences Ā· 4 level
PDF Merger versus Simple Letter: the parameters behind the verdict, then further details
ParameterPDF MergerSimple Letter
PriceFreeFree
Update frequencyEvery 9 monthsEvery 2 weeks — better
AdsNoNo
In-app purchasesYesYes
DevicesiPhone, iPadiPhone, iPad
Requires iOS17.0 — better26.0
Further details — not scored
Size2 MB5 MB
Age rating4+9+
DeveloperAhmet BostanckliogluWolfram Wacker

In-app purchases

3 purchases

PDF Merger

Subscriptions2
  • Pro — Weekly3 Days trial$1.997 Days
  • Pro — Yearly$29.991 Year
One-time1
  • PDF Merger Lifetime$59.99
3 purchases

Simple Letter

One-time3
  • Simple Letter Pro$1.99
  • Small Coffee (voluntary tip)$1.99
  • Large Coffee (voluntary tip)$5.99

Questions

Is PDF Merger free?
PDF Merger is free to download, with in-app purchases available.
Is Simple Letter free?
Simple Letter is free to download, with in-app purchases available.
Do PDF Merger or Simple Letter have ads?
Neither PDF Merger nor Simple Letter shows ads.
Which is updated more often, PDF Merger or Simple Letter?
PDF Merger ships an update every 9 months, and Simple Letter every 2 weeks. Most recently, PDF Merger was updated on October 7, 2026 and Simple Letter on October 23, 2026.

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