Comparison

COB vs Sign PDF

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

Head to head
About

COB

This electronic office solution streamlines business operations with digital document management and workflow automation. It aims to enhance efficiency and accessibility for corporate users.

Highlights
  • Electronic office solution
  • Digital document management
  • Workflow automation
  • Business operations enhancement
  • Increased efficiency
Features
Read full description

Giải pháp văn phòng điện tử dành cho doanh nghiệp

About

Sign PDF

Easily sign, fill, and scan documents directly from your iPhone. Add signatures, stamps, and text to PDFs without needing to print or use a computer. All your work stays private on your device.

Highlights
  • eSign PDFs by drawing, typing, or importing
  • Add custom stamps and seals with background removal
  • Built-in document scanner to PDF
  • Instantly fill out PDF forms
  • Save multiple signatures and stamps
  • Export flattened, device-consistent PDFs
  • Privacy-focused, on-device processing
Features
Read full description

Sign PDFs in seconds. Scan paper documents into PDF, fill out forms, add a hand-drawn signature, a business stamp or seal, date, or initials — all on your iPhone, all private. Sign PDF turns your phone into a pocket-sized document signer. Built for real life: lease agreements, NDAs, contracts, tax forms, permission slips, invoices, waivers. Scan a paper, sign it, stamp it, send it — no sign-up, no ads, no paywall on the essentials. FEATURES • eSign any PDF — draw, type, or import a signature • Import a stamp or seal — add your business stamp, company seal, or an Approved / Confidential / Date mark; the background is removed automatically, on-device • Built-in document scanner — paper to clean PDF with one tap • Fill forms instantly — tap on any field and type • Add checkboxes, dates, and text overlays • Save multiple signatures and stamps — pick the one you need per document • Export flattened PDFs that look identical on every device • Privacy by design — everything stays on your iPhone, nothing uploaded WHY WE BUILT IT Signing a PDF shouldn't require a $10/month subscription to a corporate service. Sign PDF is built by an indie studio, not a legal giant — it does one thing well and respects your time and your data. DESIGNED FOR EVERYONE - Renters signing leases from their phone - Freelancers turning around contracts on the go - Small business owners stamping and signing their paperwork - Anyone tired of printing, signing, scanning, emailing PRO (OPTIONAL) Upgrade to Sign PDF Pro to unlock: • Batch sign — send multiple PDFs in one go • iCloud sync — your signatures and stamps on every device you own • Unlimited signatures and stamps — store as many as you need • No ads forever Free tier stays free: you can always sign and scan without paying a cent. SUBSCRIPTION PRICING • Weekly — 3-day free trial, then $1.99/week • Monthly — $4.99/month • Annual — $19.99/year (best value) Payment is charged to your Apple ID at confirmation. Subscription auto-renews unless cancelled at least 24 hours before the end of the current period. Manage or cancel anytime in Settings. Terms of Use: https://pdfsign.nomly.space/terms Privacy Policy: https://pdfsign.nomly.space/privacy

Screenshots

COB4 screens
Sign PDF4 screens

Verdict

The call

The clearest difference is in-app purchases: COB at none against Sign PDF's 10. COB also leads on iOS requirement (15.5 vs 18). Sign PDF's advantage is update cadence (every 2 weeks vs every 6 weeks). On price, rating, ratings volume and ads 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. Sign PDF sells 10 in-app purchases, starting at $2.99 per 7 days. COB asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 5.0 for COB against 5.0 for Sign PDF. Both are backed by a comparable volume of ratings — 2 and 1 respectively.

UpkeepUpdate frequency

COB ships an update every 6 weeks, Sign PDF every 2 weeks. The most recent releases landed on September 8, 2026 and September 4, 2026 respectively.

Scorecard4 real differences · 5 level
COB versus Sign PDF: the parameters behind the verdict, then further details
ParameterCOBSign PDF
PriceFreeFree
Rating5.0 (2 ratings)5.0 (1 ratings)
Number of ratings2 — better1
Update frequencyEvery 6 weeksEvery 2 weeks — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFree — betterFree with in-app purchases
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS15.5 — better18
Further details — not scored
Size45 MB43 MB
Age rating4+4+
DeveloperCo-opBankDECLAN JOHN NANTON

Customer experience

COB

All ratings2 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

Sign PDF

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

In-app purchases

None

COB

No in-app purchases

10 purchases

Sign PDF

Subscriptions10
  • eSign & Fill Contracts$2.997 Days
  • Stamp, Seal & Scan Pass$3.997 Days
  • Fill Forms Pro Monthly$6.991 Month
Show 7 more
  • Paperwork Pass — 3 Months$7.993 Months
  • PDF Editor & Scanner Plan$9.991 Month
  • Sign Documents Quarterly$9.993 Months
  • Contract Kit — 3 Months$12.993 Months
  • Annual — Unlimited Signatures$19.991 Year
  • Unlimited Signatures Annual$29.991 Year
  • eSignature & Stamps Yearly$39.991 Year

Questions

Is COB free?
COB is free to download, with no in-app purchases.
Is Sign PDF free?
Sign PDF is free to download, with in-app purchases available.
Which has better reviews, COB or Sign PDF?
COB and Sign PDF are both rated 5.0 out of 5 on the App Store, from 2 and 1 ratings respectively.
Do COB or Sign PDF have ads?
Neither COB nor Sign PDF shows ads.
Which is updated more often, COB or Sign PDF?
COB ships an update every 6 weeks, and Sign PDF every 2 weeks. Most recently, COB was updated on September 8, 2026 and Sign PDF on September 4, 2026.

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