Chord Calculus vs variStretch
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Chord Calculus
This app helps musicians visualize and understand chords, scales, and progressions for various fretted instruments. It allows customization of instruments, tunings, and capos, and includes a tuner. Play chords, arpeggios, and scales.
- Chord calculator with fingering display
- Chord identifier for unknown fingerings
- Scale display and playback
- Chord progression player
- Custom instrument and tuning creation
- Capo support
- Instrument tuner
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ChordCalculus is a tool for players of fretted instruments. ChordCalculus will allow the user to choose from a large number of pre-defined fretted instruments in a variety of tunings. Additionally, the user can define new instruments and/or tunings. Single or multiple capos can be added. The user then picks from one of four operating modes using the segmented selectors at the center top of the display: * (C)hord Calculator: Show all fingerings for chords for a given instrument/tuning, filters, capos, and fret span. * Chord (I)dentifer: For a given instrument/tuning and fingering, display all possible names for a chord * (S)cale Display: For an instrument/tuning, key and scale type, display the scale, and play a two-octave scale * (P)rogression Player: Derived from chord mode, display fingerings for a chord progression. Also plays chords in sequence. In all cases, the chords can be played as a chord or arpeggio and the scale played back. As of version 2.0, an instrument tuner is accessed by long touching the tuning button. See https://www.youtube.com/watch?v=Ty5eI_DiXhk&t=20s for all the features
variStretch
This app allows real-time audio speed manipulation without altering pitch. It offers three distinct playback modes and adjustable buffer settings for precise control over sound processing.
- Real-time speed adjustment (0.5-2.0x)
- Tape mode (speed & pitch change)
- Phase Vocoder mode (speed only)
- Adjustable buffer size
- Buffer clear function
- AUv3 host compatibility
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Concept: The app is a so-called time-stretch machine. The user can change the speed (0.5-2.0) of audio source in real-time using keyboard or slider at will. Usage: There are three play modes: 1) Tape (to change the both speed & pitch) 2) Phase Vocoder (to change the speed alone) 3) Thru (no processing) "Buffer Size" slider determines how long the data will be stored. "Buffer Clear" button will reset the buffer to be zero. System Requirements: AUv3 host
Screenshots
Verdict
The clearest difference is rating: variStretch at 5.0 against Chord Calculus's 3.9. variStretch also leads on iOS requirement (12.0 vs 16.0). Chord Calculus's advantage is update cadence (fortnightly vs every 7 months) and price ($2.99 vs $5.99). On ads, in-app purchases, monetization model and device support 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
Chord Calculus costs $2.99 and variStretch $5.99 up front. Neither carries in-app purchases, so what you see is what you pay.
variStretch holds the better App Store score, 5.0 against 3.9. That said, the two scores are not equally well evidenced: Chord Calculus has 8 ratings behind it against 1, so its average is the more settled of the two.
Chord Calculus ships an update fortnightly, variStretch every 7 months. The most recent releases landed on November 2, 2026 and October 30, 2026 respectively.
| Parameter | Chord Calculus | variStretch |
|---|---|---|
| Price | $2.99 — better | $5.99 |
| Rating | 3.9 (8 ratings) | 5.0 (1 ratings) — better |
| Positive reviews | 80.0% of reviews | — |
| Number of ratings | 8 — better | 1 |
| Update frequency | Fortnightly — better | Every 7 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Paid |
| Devices | iPhone, iPad | iPhone, iPad, iPod — better |
| Requires iOS | 16.0 | 12.0 — better |
| Further details — not scored | ||
| Size | 64 MB | 15 MB |
| Age rating | 4+ | 4+ |
| Developer | Steven Pollack | Satoshi Kajii |
Customer experience
Chord Calculus
variStretch
In-app purchases
Chord Calculus
No in-app purchases
variStretch
No in-app purchases
Questions
Is Chord Calculus free?
Is variStretch free?
Which has better reviews, Chord Calculus or variStretch?
Do Chord Calculus or variStretch have ads?
Which is updated more often, Chord Calculus or variStretch?
Other comparisons
