Comparison

Sign Documents vs Key Library

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

Head to head
About

Sign Documents

Easily fill, sign, and manage documents digitally. Securely add signatures, initials, and text to PDFs imported from cloud services or your device. Export and share signed documents instantly.

Highlights
  • Securely sign PDFs
  • Import from cloud/device
  • Add initials and text
  • Save and reuse signature
  • Export and share as PDF
Features
Read full description

Effortlessly fill, sign, and manage your documents from your device. This app is designed for professionals and individuals who need a reliable and fast way to handle digital signatures on the go. Key Features: – Sign PDFs and documents securely – Import files from cloud services or your device – Add initials, dates, and custom text fields – Save and reuse your signature for convenience – Export signed documents as PDF and share instantly Subscription Details: – Weekly Plan: $4.99/week with a free trial – Annual Plan: $29.99/year - Payment will be charged to your App Store account upon confirmation of purchase. - Subscription automatically renews unless auto-renew is turned off at least 24 hours before the end of the current period. - Manage your subscription and auto-renewal settings through your Account Settings. - Any unused portion of a free trial will be forfeited when you purchase a subscription. Privacy Policy - https://docs.google.com/document/d/1muhVvCO33USdK46-LU06wfMfO6IY4n_a8V_jokk_tvU/edit?usp=sharing Terms of Use - https://docs.google.com/document/d/1y95UeXY3w7xSkk8bxXddCSGzUjZAu-NG4qRCy00Jwpg/edit?usp=sharing

About

Key Library

Features
Read full description

Everyone has a drawer, hook, or junk bin full of keys with no idea what they open. Key Library solves that — permanently. PHOTOGRAPH EVERY KEY ONCE Snap a photo of any key — house, garage, padlock, filing cabinet, mailbox — and add a quick note about what it opens. Key Library automatically reads any stamped code on the key and keeps a smart visual fingerprint of its shape and cut pattern. FIND OUT WHAT A MYSTERY KEY OPENS Found a key with no idea what it's for? Scan it with Identify Key, and Key Library checks it against everything you've already saved — flagging Exact and Likely matches so you know at a glance whether you've seen it before. BUILT FOR REAL KEY DRAWERS Works regardless of how the key is rotated or flipped when you scan it Organize by Automotive, Household, or Commercial Search and filter by notes, tags, category, or detected key codes Add a photo of both sides for extra-reliable matching ENTIRELY PRIVATE, BY DESIGN Key Library has no account, no login, and no cloud. Every photo, note, and match happens right on your iPhone using Apple's on-device Vision framework — nothing is ever uploaded anywhere. Your key drawer stays exactly as private as it already is. Free to start — catalog your first several keys at no cost, with a simple one-time upgrade if your collection grows. Stop guessing. Start knowing what every key in that drawer actually does.

Screenshots

Sign Documents4 screens
Key Library3 screens

Verdict

The call

The clearest difference is iOS requirement: Sign Documents at 16.0 against Key Library's 18.6. 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. Sign Documents sells 7 in-app purchases, starting at $2.99 per 7 days and Key Library sells 2 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

Scorecard1 real difference · 7 level
Sign Documents versus Key Library: the parameters behind the verdict, then further details
ParameterSign DocumentsKey Library
PriceFreeFree
Rating4.4 (23 ratings) — better—
Number of ratings23 — better—
AdsNoNo
In-app purchasesYesYes
MonetizationFree with in-app purchases—
DevicesiPhoneiPhone, iPad — better
Requires iOS16.0 — better18.6
Further details — not scored
Size48 MB4 MB
Age rating4+4+
DeveloperDanyil PodziraevJOSHUA ADAM PEARCE-GARCIA

In-app purchases

7 purchases

Sign Documents

Subscriptions7
  • Signature – Sign Documents3 Days trial$2.997 Days
  • Signature – Sign Documents3 Days trial$4.997 Days
  • Signature – Sign Documents3 Days trial$6.997 Days
Show 4 more
  • Signature – Sign Documents3 Days trial$9.997 Days
  • Signature – Sign Documents3 Days trial$19.991 Year
  • Signature – Sign Documents$29.991 Year
  • Signature – Sign Documents$39.991 Year
2 purchases

Key Library

One-time2
  • Standard$4.99
  • Unlimited$12.99

Questions

Is Sign Documents free?
Sign Documents is free to download, with in-app purchases available.
Is Key Library free?
Key Library is free to download, with in-app purchases available.
Do Sign Documents or Key Library have ads?
Neither Sign Documents nor Key Library shows ads.

Other comparisons