Comparison

QuickVibrator 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

QuickVibrator

This application provides a simple and handy way to generate vibrations. Users can create custom vibration patterns and control the vibration using intuitive swipe or long-press gestures.

Highlights
  • Create custom vibration patterns
  • Swipe switch ON/OFF
  • Long press switch ON/OFF
  • Handy vibration tool
Features
Read full description

QuickVibrator is a powerful, easy-to-use vibration app for strong phone vibration, custom patterns, remote control, and AI-assisted rhythm creation. MAIN FEATURES: • Adjust intensity from 0 to 100% and choose Continuous, Pulse, Wave, Heartbeat, Massage, and Unwind. • Swipe to change patterns or intensity, or hold to vibrate with Touch Mode. • Record custom rhythms, finish anytime, then preview, edit, loop, import, export, or share. • Use optional AI help to create, refine, name, polish, or find patterns. Review suggestions before saving. • Pair compatible devices on the same LAN. Start, stop, adjust intensity, or send patterns remotely; Mac and Windows can control a phone. • Set a Session Timer for up to 60 minutes and Safety Auto-Stop for up to 3 hours. • Use Blackout Mode, Control Lock, themes, and larger controls. QuickVibrator Pro removes mobile ads and desktop reminders. Terms of Use: https://kakitiro.com/quickapps/quickvibrator/terms/

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

QuickVibrator4 screens
Dúo Calculator3 screens

Verdict

The call

The clearest difference is price: QuickVibrator at Free against Dúo Calculator's $1.99. QuickVibrator also leads on device support (4 vs 1) and iOS requirement (13.0 vs 26.0). Dúo Calculator's advantage is in-app purchases (none vs 2) and ads (none vs shown). On update cadence 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

QuickVibrator is free to download; Dúo Calculator costs $1.99 up front. QuickVibrator sells 2 in-app purchases, starting at $0.99 per year. Dúo Calculator asks for nothing beyond the download.

UpkeepUpdate frequency

QuickVibrator ships an update every 4 months, Dúo Calculator every 6 months. The most recent releases landed on October 24, 2026 and October 28, 2026 respectively.

Scorecard5 real differences · 5 level
QuickVibrator versus Dúo Calculator: the parameters behind the verdict, then further details
ParameterQuickVibratorDúo Calculator
PriceFree — better$1.99
Rating2.8 (305 ratings) — better—
Positive reviews68.3% of reviews—
Number of ratings305 — better—
Update frequencyEvery 4 months — betterEvery 6 months
AdsYesNo — better
In-app purchasesYesNo — better
MonetizationFree—
DevicesiPhone, iPad, iPod, Mac — betteriPhone
Requires iOS13.0 — better26.0
Further details — not scored
Size44 MB3 MB
Age rating4+4+
DeveloperKAZUHIRO KAKIMOTOAlejandro Hernandez Mitre

Bugs and requests

QuickVibrator

Reported bugs

3 issues
  • App doesn't vibrate
  • App doesn't work on certain iPhones
  • Cannot delete the app

Requested features

3 requests
  • Add speed settings
  • Create a version for men
  • Option for patterns or no pattern

Dúo Calculator

Not enough reviews yet to summarise bugs or requests.

In-app purchases

2 purchases

QuickVibrator

Subscriptions1
  • Pro - Annual$0.991 Year
One-time1
  • Pro - Lifetime$5.99
None

Dúo Calculator

No in-app purchases

Questions

Is QuickVibrator free?
QuickVibrator is free to download, with in-app purchases available.
Is Dúo Calculator free?
Dúo Calculator costs $1.99, with no in-app purchases.
Do QuickVibrator or Dúo Calculator have ads?
QuickVibrator shows ads; Dúo Calculator does not.
Which is updated more often, QuickVibrator or Dúo Calculator?
QuickVibrator ships an update every 4 months, and Dúo Calculator every 6 months. Most recently, QuickVibrator was updated on October 24, 2026 and Dúo Calculator on October 28, 2026.

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