QuickVibrator vs Dúo Calculator
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
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.
- Create custom vibration patterns
- Swipe switch ON/OFF
- Long press switch ON/OFF
- Handy vibration tool
Read full descriptionHide 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/
Dúo Calculator
Read full descriptionHide 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
Verdict
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
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.
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.
| Parameter | QuickVibrator | Dúo Calculator |
|---|---|---|
| Price | Free — better | $1.99 |
| Rating | 2.8 (305 ratings) — better | — |
| Positive reviews | 68.3% of reviews | — |
| Number of ratings | 305 — better | — |
| Update frequency | Every 4 months — better | Every 6 months |
| Ads | Yes | No — better |
| In-app purchases | Yes | No — better |
| Monetization | Free | — |
| Devices | iPhone, iPad, iPod, Mac — better | iPhone |
| Requires iOS | 13.0 — better | 26.0 |
| Further details — not scored | ||
| Size | 44 MB | 3 MB |
| Age rating | 4+ | 4+ |
| Developer | KAZUHIRO KAKIMOTO | Alejandro 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
QuickVibrator
- Pro - Annual$0.991 Year
- Pro - Lifetime$5.99
Dúo Calculator
No in-app purchases
Questions
Is QuickVibrator free?
Is Dúo Calculator free?
Do QuickVibrator or Dúo Calculator have ads?
Which is updated more often, QuickVibrator or Dúo Calculator?
Other comparisons















