Comparison

NMR Tutor vs Rondo

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

Head to head
About

NMR Tutor

Explore NMR data acquisition and signal processing with interactive simulations. Adjust parameters like noise, apodization, and phase to observe immediate effects on FID and spectra. Learn about common artifacts and advanced concepts like spin-spin coupling.

Highlights
  • Interactive FID and spectra simulations
  • Adjustable peak positions and decay
  • Noise and apodization control
  • Zero filling and phase correction
  • Simulate acquisition artifacts
  • Explore spin-spin coupling
Features
Read full description

NMR Tutor is an interactive introduction to NMR data acquisition and signal processing. Use simulated free induction decays (FIDs) and spectra to explore how time-domain NMR signals become frequency-domain spectra. Adjust peak positions, decay, noise, apodization, zero filling, phase behavior, and common acquisition artifacts, then see the effect immediately in the FID and final spectrum. The app displays real and imaginary FID channels before and after processing, together with the resulting spectrum after Fourier transformation. A live signal-to-noise (S/N) measurement updates as you adjust noise, scan averaging, apodization, FID artifacts, and shimming, making processing tradeoffs easy to compare. Apply zero filling to see how digital interpolation changes the appearance of the spectrum without adding new measured data. You can also introduce common receiver or acquisition faults into the FID and observe the artifacts that appear after processing. As an advanced example, add spin-spin coupling to create an AB coupling pattern, then move the peaks or change the coupling strength to compare AB behavior with an AX spin system. Charts retain every data point and support pan, zoom, phase-pivot dragging, graph audio, sharing and export, and external displays. Optimized Metal and Accelerate processing keeps high-resolution chart and shimming interactions responsive. Adaptive layouts and larger accessibility text make the workspace easier to use on iPhone, iPad, and Mac. Open one-dimensional JEOL, Bruker and Varian FID datasets directly. Inspect the acquired real and imaginary channels, then apply apodization, zero filling, first-point scaling, and zero- and first-order phase correction to your own data.

About

Rondo

Explore the mathematical beauty of numbers through interactive, animated factorization diagrams. Watch numbers dance, hear their unique songs, and even visualize them in augmented reality. Discover the stories behind special numbers and personalize your experience with customizable palettes and sounds.

Highlights
  • Animated factorization diagrams
  • Augmented reality number visualization
  • Auditory representation of factors
  • Interactive number exploration
  • Field Guide for special numbers
  • Home screen and Apple Watch widgets
  • Customizable color palettes and sounds
Features
Read full description

Rondo turns the counting numbers into a quiet, hypnotic dance. Every number from 1 upward is drawn as a factorization diagram: nested rings of colored dots that show, at a glance, how that number is built from its prime factors. 6 is two groups of three. 12 is three groups of four. Primes can't be split, so they shimmer alone. Then the diagram melts and re-forms into the next number, and the next, an endless looping dance of arithmetic. It's equal parts math toy, teaching tool, and ambient art. WATCH, OR EXPLORE • Let it play for a calm, continuous dance from one number to the next • Tap to pause, drag to scrub to any number, or step one at a time • Speed it up, or slow it right down • A gentle haptic tap each time the dance lands on a prime • Follow any number down its Collatz orbit, and watch it fall back to 1 HEAR IT • Every number sings its factorization: a prime is a single pure tone, a composite a chord of its prime factors • On by default, off whenever you like POINT YOUR CAMERA • Aim Rondo at any printed number and watch its diagram bloom over the page, in augmented reality • Summon a number's diagram into the room, then walk around it • Street signs, receipts, book pages: factor the world around you EVERY NUMBER HAS A STORY • Tap any number to see what makes it special: whether it's prime, a perfect number, a power, and more • Collect the special numbers you find in the Field Guide SEE THE MATH • The current number and its factorization, always in view • Full VoiceOver support and a spoken read-out of each number and how it factors • Save the numbers you love to Favorites, and share any diagram as an image ON YOUR HOME SCREEN AND WRIST • Widgets that turn today's date into factorization diagrams, across the Home Screen, Lock Screen, and StandBy • A factorization calendar for the month or the current week • A widget for a number you pin, and a stepper widget you tap to walk one number at a time • An Apple Watch app: scrub through the numbers with the Digital Crown, with the same prime haptics • Ask Siri for a number, or add Rondo to a Shortcut • An optional nudge on days whose number is itself worth a look MAKE IT YOURS WITH RONDO PRO A one-time unlock, never a subscription. The full dance stays free. Pro is for going deeper: • New color palettes, backgrounds, and color styles • Layout options for how the rings nest and order themselves • A living clock face that factors the time • Number sequences: count by multiples, primes only, Fibonacci, and more • The full instrument: tune the scale, voice, and space of the sound • Hear any number's story narrated aloud, in your choice of tone CALM BY DESIGN No ads. No tracking. No account. No subscription. Rondo is free to play, with an optional one-time Pro unlock. A LOVING HOMAGE Rondo is a faithful tribute to Brent Yorgey's factorization diagrams and Stephen Von Worley's animated "Factor Conga," built natively for iPhone, iPad, and Apple Watch. The diagrams honor their work; the sound, the augmented reality, and the stories are Rondo's own. Full credits are in the app.

Screenshots

NMR Tutor4 screens
Rondo4 screens

Verdict

The call

The clearest difference is in-app purchases: NMR Tutor at none against Rondo's 5. NMR Tutor also leads on iOS requirement (17.6 vs 26.0). Rondo's advantage is update cadence (every 3 days vs fortnightly). On price, rating, ratings volume and 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

Both are free to download. Rondo sells 5 one-off in-app purchases. NMR Tutor asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 5.0 for NMR Tutor against 5.0 for Rondo. Both are backed by a comparable volume of ratings — 1 and 1 respectively.

UpkeepUpdate frequency

NMR Tutor ships an update fortnightly, Rondo every 3 days. The most recent releases landed on October 10, 2026 and October 28, 2026 respectively.

Scorecard4 real differences · 5 level
NMR Tutor versus Rondo: the parameters behind the verdict, then further details
ParameterNMR TutorRondo
PriceFreeFree
Rating5.0 (1 ratings)5.0 (1 ratings)
Number of ratings11
Update frequencyFortnightlyEvery 3 days — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFree — betterFree with in-app purchases
DevicesiPhone, iPad, MaciPhone, iPad, Apple Watch
Requires iOS17.6 — better26.0
Further details — not scored
Size7 MB11 MB
Age rating4+4+
DeveloperTim E. BurrowKEN TOMINAGA

Customer experience

NMR Tutor

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

Rondo

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

NMR Tutor

No in-app purchases

5 purchases

Rondo

One-time5
  • Tip a prime · 199$1.99
  • Tip a prime · 499$4.99
  • Rondo Pro$4.99
Show 2 more
  • Tip a prime · 599$5.99
  • Tip a prime · 1999$19.99

Questions

Is NMR Tutor free?
NMR Tutor is free to download, with no in-app purchases.
Is Rondo free?
Rondo is free to download, with in-app purchases available.
Which has better reviews, NMR Tutor or Rondo?
NMR Tutor and Rondo are both rated 5.0 out of 5 on the App Store, from 1 and 1 ratings respectively.
Do NMR Tutor or Rondo have ads?
Neither NMR Tutor nor Rondo shows ads.
Which is updated more often, NMR Tutor or Rondo?
NMR Tutor ships an update fortnightly, and Rondo every 3 days. Most recently, NMR Tutor was updated on October 10, 2026 and Rondo on October 28, 2026.

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