Comparison

QR Code Reader vs Dúo Calculator

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

Head to head
About

QR Code Reader

Easily scan and interpret various QR codes, including URLs, Wi-Fi, and contact information. Generate custom QR codes for social media, websites, and more. Seamlessly integrate codes into Apple Wallet and widgets, with a convenient scan history and backup feature.

Highlights
  • Scan all QR code types
  • Generate custom QR codes
  • Integrate codes into Apple Wallet
  • Add codes to Widgets
  • Scan from images
  • Scan history and backup
Features
Read full description

Lilucat's QR Code Reader is the essential digital tool that empowers you to scan and interpret all types of QR codes, encompassing URLs, Wi-Fi, Calendar events, VCards, Contacts, Text, Email, Geo locations, and more. Beyond just scanning, Lilucat's QR Code Reader also facilitates the generation of QR codes for a myriad of purposes, be it social media platforms (like TikTok, YouTube, Facebook, etc.), URLs, Wi-Fi networks, VCards, Contact details, and beyond. Key Features: Rapid QR code scanning. Dynamic QR code generation. Integrate codes directly into Apple Wallet. Conveniently add codes to Widgets. Scan QR codes and barcodes directly from images. Maintain a comprehensive scan history. Sync and ensure your scans are always backed up. * In order to use QR Code Reader you need to purchase the Lilucat Pro which is an annual service that costs 29.99$. Payment will be charged to iTunes Account at confirmation of purchase and auto-renews at the same price unless disabled in iTunes Account Settings at least 24 hours before the end of the current period. Your subscription can be managed in your iTunes Account Settings. Any unused portion of a free trial period, if offered, will be forfeited when you purchase a subscription. Links Terms of Service: https://qrcode.lilucat.com/legal/terms Privacy: https://qrcode.lilucat.com/legal/privacy

About

Dúo Calculator

Features
Read full description

Now compatible with iPhone Duo. LiquidCalculator is now Dúo Calculator: fold your iPhone Duo and it's a basic calculator; unfold it and it becomes a full scientific calculator. On any iPhone: a basic or scientific keypad, a unit converter and your calculation history, with a precise math engine. No ads, no account and no in-app purchases. ONE CALCULATOR, TWO SCREENS • Folded: a basic calculator with big keys. In landscape, a compact scientific keypad appears (you can turn it off in Settings). • Unfolded: a 10 × 5 scientific keypad with every function in view; with the screen flat, also programmer mode and a unit converter. • Half open like a laptop, the result sits above the fold and the keypad below it. Open like a book, the keypad splits across both sides of the fold. • Fold or unfold in the middle of a calculation and your work stays put: keys slide to their new places and the new ones appear. • It also adapts to Split View on the inner display. ON YOUR IPHONE • Pick Basic or Scientific from the menu, in portrait or landscape. • Unit converter and History on every model. • iPhone SE and accessibility text sizes keep the big basic keys. HISTORY • Your last 50 calculations, newest first • Tap a result to use it again; swipe to delete one, or clear them all • On an unfolded iPhone Duo it opens in a panel that never crosses the fold A REAL SCIENTIFIC CALCULATOR • Trigonometry in degrees or radians, inverse and hyperbolic functions • ln, log10, log2 and logarithms in any base • Powers, roots of any degree, factorial, 1/x, π, e and EE notation • Parentheses, memory (mc, m+, m−, mr) and the 2nd key • Live result as you type, plus cursor editing: tap the expression to fix any point It does not include graphing, matrices or statistics. EXACT UNDER THE HOOD Basic operations use exact fractions: 0.1 + 0.2 gives 0.3 and 1 ÷ 3 × 3 gives 1. Functions such as sin, ln or e^x are computed with 60 digits of precision and the display shows up to 16. Invalid operations, such as dividing by zero or tan 90°, show a clear error instead of a wrong answer. The engine is checked against an independent reference model on hundreds of test cases. PROGRAMMER MODE (large screens, such as an unfolded iPhone Duo) • 8, 16, 32 and 64-bit integers, signed or unsigned • BIN, OCT, DEC and HEX at once, with a bit grid you can tap • AND, OR, XOR, NOR, NOT, shifts, rotations, 1's and 2's complement, mod UNIT CONVERTER • 87 units in 11 categories: length, mass, temperature, area, volume, speed, time, data, energy, pressure and angle • Swap units with one tap, pull in the calculator's value or send the result back to it • Works offline; currencies are not included YOUR WAY • Light, dark or system theme, with optional pure OLED black • Four accent colors: amber, indigo, mint and graphite • Liquid Glass design; haptics and the aurora background are optional • Copy and paste, plus hardware keyboard support • English and Spanish, with VoiceOver labels; respects Reduce Motion, Reduce Transparency and Increase Contrast PRIVATE BY DESIGN • Collects no data: no account, no ads, no analytics, no tracking • Never uses the network: the app never sends your calculations anywhere • Settings, your last calculation and your History are stored on the device (and in its backups) and removed from it with the app COMPATIBILITY • Now compatible with and optimized for iPhone Duo, on both the outer and the inner display. • Runs on any iPhone with iOS 26 or later. Programmer mode needs a large screen, such as the inner display of iPhone Duo. • iPhone only. Support and feedback: alex@nextechia.dev iPhone and iPhone Duo are trademarks of Apple Inc. This app is independent and is not affiliated with Apple.

Screenshots

QR Code Reader4 screens
Dúo Calculator3 screens

Verdict

The call

The clearest difference is price: QR Code Reader at Free against Dúo Calculator's $1.99. QR Code Reader also leads on update cadence (every 10 days vs every 6 months) and device support (4 vs 1). Dúo Calculator's advantage is in-app purchases (none vs 4). On 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

QR Code Reader is free to download; Dúo Calculator costs $1.99 up front. QR Code Reader sells 4 in-app purchases, starting at $7.99 per 7 days. Dúo Calculator asks for nothing beyond the download.

UpkeepUpdate frequency

QR Code Reader ships an update every 10 days, Dúo Calculator every 6 months. The most recent releases landed on October 24, 2026 and October 28, 2026 respectively.

Scorecard5 real differences · 5 level
QR Code Reader versus Dúo Calculator: the parameters behind the verdict, then further details
ParameterQR Code ReaderDúo Calculator
PriceFree — better$1.99
Rating4.7 (128 ratings) — better—
Positive reviews24.1% of reviews—
Number of ratings128 — better—
Update frequencyEvery 10 days — betterEvery 6 months
AdsNoNo
In-app purchasesYesNo — better
MonetizationSubscription—
DevicesiPhone, iPad, iPod, Mac — betteriPhone
Requires iOS15.0 — better26.0
Further details — not scored
Size53 MB3 MB
Age rating4+4+
DeveloperLilucatAlejandro Hernandez Mitre

In-app purchases

4 purchases

QR Code Reader

Subscriptions2
  • QR Code Scanner3 Days trial$7.997 Days
  • QR Code Reader$29.991 Year
One-time2
  • QR Code ReaderFree
  • QR Code Scanner$59.99
None

Dúo Calculator

No in-app purchases

Questions

Is QR Code Reader free?
QR Code Reader is free to download, with in-app purchases available.
Is Dúo Calculator free?
Dúo Calculator costs $1.99, with no in-app purchases.
Do QR Code Reader or Dúo Calculator have ads?
Neither QR Code Reader nor Dúo Calculator shows ads.
Which is updated more often, QR Code Reader or Dúo Calculator?
QR Code Reader ships an update every 10 days, and Dúo Calculator every 6 months. Most recently, QR Code Reader was updated on October 24, 2026 and Dúo Calculator on October 28, 2026.

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