Sing vs VAPolyMk4
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Sing
Visualize your singing or instrument playing pitch with a color-coded graph. This app analyzes audio input to show if you are on, sharp, or flat, helping you train your ear for accurate intonation.
- Color-coded pitch graph
- Real-time audio analysis
- Visualizes pitch accuracy
- Supports singing and instruments
- Pitch frequency spectrum display
- Monophonic pitch detection
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Can you sing in tune? Learn to sing (or play an instrument) accurately in tune with HotPaw Sing-inTuna's color-coded pitch graph. Sing-inTuna uses the built-in microphone on your iPhone or iPad to analyze and help you visualize if you are singing, or playing a musical instrument (such as a violin), precisely on the right pitch. It graphs pitch on a scrolling graph resembling a musical Grand Staff. Tones that are on-pitch (+-20 cents) are colored green; notes slightly sharp: red; notes a pinch flat: blue. You can also display an optional pitch frequency spectrum of your voice to see your timbre. Sing-inTuna requires a quiet environment with no accompaniment or harmony, and monophonic pitches that are at least a quarter second long. The pitch range using the built-in mic is about +-2 octaves from middle-C, depending on microphone use, loudness, and timbre. Note: This app produces no sounds and shows no sheet music. It only listens so that you can see your pitch, and how well your pitch matches that of a well tuned equal-temperament instrument.
VAPolyMk4
This app is a powerful bi-timbral polyphonic synthesizer with advanced features like output morphing and a ring modulator. It offers extensive sound design capabilities with multiple oscillators, filters, and envelopes, and can be used standalone or as an AudioUnit Extension.
- Bi-timbral polyphonic synthesis
- Output morphing and ring modulator
- Multiple oscillators, filters, and envelopes
- Standalone and AudioUnit Extension (AUv3) support
- Built-in effects and piano roll sequencer
- MIDI 2.0 and Ableton Link support
- iCloud Drive for project sharing
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VAPolyMk4 is bi-timbral polyphonic synthesizer, which features output morphing, classic ring modulator and global offset parameter control. Each synthesizer consists of three oscillators, resonant low pass and hight pass filter, amplifier, three envelope generators and two LFO. Two synthesizers can be configured as layer or split. VAPolyMk4 operates as a stand alone or as an AudioUnit Extension (AUv3) for iPhone, iPad and Mac. Stand Alone supports Ableton Link, MIDI and audio file export. Built-in Effects include delay, chorus, flanger, reverb, eq and compressor. Project files can be saved in iCloud Drive, so that the project can be accessed from iPhone, iPad or Mac. Main Features Bi-timbral Polyphonic Synthesizer. Output morphing. Classic Ring Modulator. Global Offset Parameter Control. Three oscillators featuring hard sync and through zero FM. Maximum 8 voice polyphony. it depends on performance of the device it is running. Built-in effects and piano roll sequencer. Audio Export. Linear PCM format (AIFF, WAV and CAF) and compressed format (AAC) Support Audio Unit Extension (AUv3). Support MIDI 2.0. Support Foot Pedal and Per Note Control. Support Ableton Link, Bluetooth MIDI, MIDI In / Out. Works on iPhone, iPad and Mac. Support iCloud Drive to share project files between the platforms. Full Factory Preset: 230, Synth CH: 160, Effect: 40 Improvements Support MIDI Foot Pedal (CC#11, CC#64) Support MIDI2.0 Per Note Control Messages MIDI CC Settings are saved. It will be recovered when the app launched in the next time. UI Color can be selected from black, navy or gray. System Requirements iOS 17.0 or later Devices with Apple Silicon are recommended. A13 Fusion or above is highly recommended. if sound is distorted when using a device with less CPU power, reduce number of voices. AudioUnit Extension (AUv3) requires host application which support AudioUnit Extension. AudioUnit Extension is supported by Apple Logic and Apple Garage Band on iOS and macOS. For any other DAW, it depends on the application and some of them don’t support AudioUnit Extension.
Screenshots
Verdict
The clearest difference is rating: VAPolyMk4 at 5.0 against Sing's 3.0. VAPolyMk4 also leads on review sentiment (100% vs 63%) and update cadence (every 2 months vs every 6 months). On ratings volume, ads, in-app purchases and monetization model 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
Sing costs $4.99 and VAPolyMk4 $3.99 up front. Neither carries in-app purchases, so what you see is what you pay.
VAPolyMk4 holds the better App Store score, 5.0 against 3.0. Both are backed by a comparable volume of ratings — 2 and 2 respectively. Written reviews point the same way: 63% of Sing's written reviews are positive against 100% of VAPolyMk4's.
Sing ships an update every 6 months, VAPolyMk4 every 2 months. The most recent releases landed on October 29, 2026 and October 30, 2026 respectively.
| Parameter | Sing | VAPolyMk4 |
|---|---|---|
| Price | $4.99 | $3.99 — better |
| Rating | 3.0 (2 ratings) | 5.0 (2 ratings) — better |
| Positive reviews | 62.5% of reviews | 100.0% of reviews — better |
| Number of ratings | 2 | 2 |
| Update frequency | Every 6 months | Every 2 months — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Paid |
| Devices | iPhone, iPad, iPod | iPhone, iPad, Mac |
| Requires iOS | 15.6 — better | 16.6 |
| Further details — not scored | ||
| Size | 2 MB | 20 MB |
| Age rating | 4+ | 4+ |
| Developer | HotPaw Productions | Ryo Togawa |
Customer experience
Sing
VAPolyMk4
In-app purchases
Sing
No in-app purchases
VAPolyMk4
No in-app purchases









