Core Synth Free vs HD
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Core Synth Free
Create music with a monophonic synthesizer featuring dual oscillators, adjustable filters, and envelope shaping. Explore various wave patterns and octaves to craft unique sounds for live performance or composition.
- Dual overlapping oscillators
- Four wave patterns
- Adjustable low pass filter
- ADSR envelope shaping
- 1 octave keyboard
- Save and load patches
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Get your groove on with Core Synth Free, the definitive monophonic synthesizer for the iPhone and iPod touch. With tons of features packed into a small package, Core Synth is great for live performing. This free app has the following features: - 1 Octave keyboard - Keys light up in different colors when pressed Oscillator Module - Dual overlapping oscillators - Four wave patterns: Square, Triangle, Sawtooth and Reverse Sawtooth * Select from 5 octaves * Adjust glide between notes * Fine tune Oscillator 2 with option to sync with Oscillator 1 Volume Envelope Shaper - Edit ADSR (Attack, Decay, Sustain, Release) Low Pass Filter Module - Adjust Cutoff and Resonance - Edit ADSR (Attack, Decay, Sustain, Release) Upgrade to the full version within the app for the following additional features: - 7 Octave Keyboard - Octave control to move along entire range Patches Module - Save an unlimited number of individually named patches - Browse through your collection before applying patch - Delete unwanted patches - Backup patches via iTunes File Sharing Modulation Module - Four wave patterns: Square, Triangle, Sawtooth and Reverse Sawtooth - Modulate Filter, Pitch or Wave - Adjust LFO Rate and amount Arpeggiator Module - Arpeggio moves up to 5 octaves - Four step modes: Up, Down, Up/Down, Random - Adjust rate Many more exciting enhancements to follow! Core Synth Free includes open source code from MobileSynth developed by Allen Porter.
HD
This application connects to a specific device via Bluetooth to remotely control musical functions. It allows instructors to guide students with features like metronome operation, tempo setting, and pitch adjustment. It also includes tools for chord detection and tuning.
- Remote HD control (keyboard, metronome, temperament, transposition)
- Customizable beat and tempo settings
- Individual volume and pitch adjustment
- Demonstrate mode for pitch and volume feedback
- Chord detection and naming
- Adjustable tuner
- Rhythm assistant
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* The device on which this application is installed must be connected to the HD-300 via Bluetooth®. The application does not produce sound independently. The HD-300 Assistant application allows an instructor to remotely control the HD-300 and provide intuitive guidance to students. ≪ Functions ≫ • HD Control In addition to keyboard and metronome operation, the app allows remote control of temperament and transposition. • Beat, Tempo Setting Irregular meter and tempos can easily be created, saved, and played back. • Individual Volume and Pitch Fine adjustment is available for individual volumes and pitches. • Demonstrate Mode The interference beat that occurs when notes are slightly out of tune can be recreated, and the volumes of harmony notes can be adjusted to give students a feel for appropriate pitch and volume. • Chord Detector Chords can be detected and named based on a group of played notes. • Tuner The tuner provides a convenient means to check pitch. The tuner’s base pitch is adjustable. ・ Rhythm Assistant The app can play the same rhythm as musical score.
Screenshots
Verdict
The clearest difference is rating: HD at 5.0 against Core Synth Free's 2.9. HD also leads on in-app purchases (none vs 1). Core Synth Free's advantage is iOS requirement (8.0 vs 13.0). On price, ratings volume, update cadence 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
Both are free to download. Core Synth Free sells 1 one-off in-app purchase. HD asks for nothing beyond the download.
HD holds the better App Store score, 5.0 against 2.9. Both are backed by a comparable volume of ratings — 8 and 3 respectively.
Core Synth Free ships an update every 13 months, HD every 10 months. The most recent releases landed on June 8, 2026 and July 20, 2026 respectively.
| Parameter | Core Synth Free | HD |
|---|---|---|
| Price | Free | Free |
| Rating | 2.9 (8 ratings) | 5.0 (3 ratings) — better |
| Positive reviews | 63.6% of reviews | — |
| Number of ratings | 8 — better | 3 |
| Update frequency | Every 13 months | Every 10 months — better |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases | Free — better |
| Devices | iPhone, iPod | iPhone, iPad, iPod — better |
| Requires iOS | 8.0 — better | 13.0 |
| Further details — not scored | ||
| Size | 7 MB | 76 MB |
| Age rating | 4+ | 4+ |
| Developer | Core Engine Apps | Yamaha Corporation |
Customer experience
Core Synth Free
HD
In-app purchases
Core Synth Free
- Full Version Upgrade$0.99
HD
No in-app purchases









