Comparison

KeyFlow AI vs PenSign

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

Head to head
About

KeyFlow AI

Enhance your writing with an AI-powered keyboard. Instantly rewrite messages in different tones, fix grammar, translate languages, and dictate with accurate transcription. Save frequently used phrases and replay past actions seamlessly within any app.

Highlights
  • Rewrite messages with different tones
  • Instant spelling and grammar correction
  • Translate to over 50 languages
  • Whisper-powered dictation
  • Save and reuse text snippets
  • Replay recent actions
Features
Read full description

Type it messy. Send it right. KeyFlow is an iPhone keyboard with AI writing tools in the row above your keys. Write your message the way you'd say it, then tap once to fix the grammar, make it shorter, change the tone or translate it. Every change is highlighted before it replaces your text, and the original is one tap away. ONE ROW, EVERY APP • Fix Grammar: spelling, punctuation and grammar. • Improve Writing and Make Shorter. • Change Tone: professional, friendly, casual or formal. • Translate between English and Spanish. • Explain This and Ask AI, without leaving the chat. • Snippets: save the lines you type every week and send them in one tap. • Your own actions: write a prompt once and it becomes a button. WRITE IN YOUR LANGUAGE AI actions reply in the language you wrote in, so they work in many languages. Typing, autocorrect and predictions are in English and Spanish; switch with the globe key. FIX JUST ONE SENTENCE Select a sentence and KeyFlow rewrites only that part. The rest of your message stays exactly as you wrote it. PREFER TO TALK? Record in the KeyFlow app and use the transcription in your writing. Dictation needs microphone access and an internet connection. START FREE Eligible installs include a limited AI trial and the full keyboard. Choose KeyFlow Pro for managed AI with nothing to set up, or Lifetime BYOK: pay once and use your own OpenAI API key, billed by OpenAI separately. Pro has usage limits. Plans, limits and your local price are shown in the app before you buy. Restore purchases at any time. YOU DECIDE WHAT'S SHARED Ordinary typing shares nothing with AI. An AI action sends the text you selected to OpenAI (with nothing selected, the current field); dictation sends the recorded audio. AI sharing needs your permission and can be turned off in Settings. Keyboard AI also needs iOS Full Access. No KeyFlow account. Works in Messages, Mail, Notes, WhatsApp and other apps with standard text fields. Password fields always use the system keyboard. Support: hello@lumozz.com Privacy: https://keyflow.lumozz.com/privacy.html Terms: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

About

PenSign

Features
Read full description

Make a signature you're proud of, then sign anything with it. Type your name and watch the pen write it in one of 12 signature styles or set it in 8 designer lettering styles, draw your own with a finger or Apple Pencil, or photograph the one you already sign on paper. Then scan a document and sign it in seconds. Everything happens on your iPhone or iPad. No account, no uploads: your signature stays yours. SIGNATURE STYLES • Type your name and watch it signed stroke by stroke, the way a pen writes • 20 styles in six groups: business, elegant, casual, bold, printed and lettering • Not quite right? Tap for another version of the same style • Five ink colours, from classic black to navy and coral • Save it like any signature and use it everywhere DRAW OR CAPTURE YOUR OWN • Draw with your finger or Apple Pencil, with three pen styles and a guide line • Photograph the signature you already write: PenSign squares up the paper, lifts the ink off the page and removes the background • Refine it: ink strength, thickness, specks and crop, with a before-and-after view • Keep initials alongside full signatures SCAN AND SIGN • Scan paper documents right in the app. PenSign finds the signature line and puts your signature on it • Or import a PDF, or a photo of a document: photos are cropped and squared up just like a scan • Add initials, text, dates and checkmarks, then tap Sign to flatten everything into the page • Sign every page at once; rotate, reorder, add and delete pages • Open password-protected PDFs • Scans stay small, so signed copies fit easily in an email OWN IT AS A FILE • Transparent PNG at print resolution • True SVG vector, built from the real strokes, so it stays sharp at any size • PDF stamp for documents that expect one • Save to Photos, copy it into Mail, Notes or Pages, or share it to any app PRIVATE BY DESIGN Capture, scanning, signing and export all run on your device. Nothing is uploaded, and there is no account to create. Optional iCloud sync keeps your library on your own devices, in your own private iCloud, not on our servers. • Face ID vault locks your signature library • Every edit is kept in version history, so an earlier version is always one tap away AUTOMATE IT Shortcuts actions sign a PDF or fetch your signature image from anywhere in iOS: the Share sheet, Siri, Spotlight and your own automations. Long-press the PenSign icon to scan a document or start a new signature. FREE TO TRY, ONE PRICE TO UNLOCK PenSign is free to try: keep one signature, sign up to three documents and use 13 of the 20 signature styles. The one-time unlock, a single purchase and not a subscription, adds unlimited signatures and initials, unlimited signed documents, every signature style, SVG export, iCloud sync, Shortcuts and the Face ID vault. Buy it once and it's yours. Terms of use: https://muxtor141.github.io/pensign-legal/terms.html Privacy policy: https://muxtor141.github.io/pensign-legal/privacy.html

Screenshots

KeyFlow AI4 screens
PenSign4 screens

Verdict

The call

KeyFlow AI and PenSign are too close to call on the numbers: across 6 compared parameters — price, update cadence, ads and in-app purchases among them — neither pulls far enough ahead to decide it. What separates them is feature set and interface, not measurable difference.

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. KeyFlow AI sells 3 in-app purchases, starting at $4.99 per month and PenSign sells 2 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

Both ship on a similar rhythm, roughly fortnightly. The most recent releases landed on October 28, 2026 and October 24, 2026 respectively.

ScorecardNo meaningful differences
KeyFlow AI versus PenSign: the parameters behind the verdict, then further details
ParameterKeyFlow AIPenSign
PriceFreeFree
Rating5.0 (1 ratings) — better—
Number of ratings1 — better—
Update frequencyFortnightlyFortnightly
AdsNoNo
In-app purchasesYesYes
MonetizationFreemium—
DevicesiPhoneiPhone, iPad — better
Requires iOS18.017.4 — better
Further details — not scored
Size19 MB19 MB
Age rating4+4+
DeveloperLumozzAbdumukhtor Turgunboev

In-app purchases

3 purchases

KeyFlow AI

Subscriptions2
  • KeyFlow Pro$4.991 Month
  • KeyFlow Pro$39.991 Year
One-time1
  • KeyFlow BYOK Lifetime$14.99
2 purchases

PenSign

One-time2
  • PenSign Lifetime$9.99
  • PenSign Unlimited$14.99

Questions

Is KeyFlow AI free?
KeyFlow AI is free to download, with in-app purchases available.
Is PenSign free?
PenSign is free to download, with in-app purchases available.
Do KeyFlow AI or PenSign have ads?
Neither KeyFlow AI nor PenSign shows ads.
Which is updated more often, KeyFlow AI or PenSign?
KeyFlow AI ships an update fortnightly, and PenSign fortnightly. Most recently, KeyFlow AI was updated on October 28, 2026 and PenSign on October 24, 2026.

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