Core Synth HD vs Retro Synth
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Core Synth HD
Create music with a powerful monophonic synthesizer for iPad. Explore dual oscillators, customizable filters, and an arpeggiator. Save your custom sounds and enhance your live performances with intuitive controls.
- Dual overlapping oscillators
- Four wave patterns
- Low Pass Filter with ADSR
- Volume Envelope Shaper (ADSR)
- Arpeggiator with multiple modes
- Save unlimited patches
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Top free iPad music app in 5 countries, top 10 in more than 50! Get your groove on with Core Synth HD, the definitive monophonic synthesizer for the iPad. With tons of features packed into a small package, Core Synth is great for live performing. A Pitch Wheel replicates perfectly the real thing! This free app has the following features: - Pitch Wheel - 2 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 - Modulation Wheel Patches Module - Save an unlimited number of individually named patches - Browse through your collection before applying patch - Delete unwanted patches 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 HD includes open source code from MobileSynth developed by Allen Porter.
Retro Synth
Create authentic retro music with this vintage-inspired synthesizer app. Explore sound design with tone controls and vibrato, or upgrade for premium waveforms and studio effects. Designed for instant musical creativity, it offers a portable music-making experience.
- Authentic vintage sound recreation
- Tone control for sound shaping
- Vibrato effect for musical expression
- Zero latency real-time response
- Premium waveforms (Sine, Sawtooth, Triangle)
- Studio effects (Reverb, Delay)
- MIDI export
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Play a real pocket stylophone — then plug it straight into GarageBand. Retro Synth · Syntophone turns your device into a vintage touch-keyboard synthesizer, and now works as an AUv3 instrument inside GarageBand, Logic Pro, and AUM. Slide your finger across the keys and a warm, authentic square-wave synth comes to life. Learn built-in songs with light-up "follow the key" tutorials, record your ideas, and drop the instrument into your favorite music app — all from one tiny synth. Like the original, it plays one note at a time: one stylus, one note. Curious about Pro? Tap any locked sound and hear it free for 30 seconds. FREE FEATURES (Included at no cost): • Authentic Vintage Sound: faithfully recreates that iconic square-wave tone with modern precision. • Song Mode: learn songs with light-up "follow the key" tutorials, hold-to-repeat for repeated notes, and a star rating when you finish (2 songs free). • My Recordings: a full library to play back, rename, share, and delete your takes. • Metronome: a sample-accurate click with adjustable BPM and an accented downbeat to keep you in time. • AUv3 Instrument: use Syntophone as a plug-in inside GarageBand, Logic Pro, AUM and other AUv3 hosts. • Sound Controls: shape your tone from thin and bright to thick and warm, and add expression with vibrato. • Real-time Response: instant, zero-latency audio as you play. • Clean, minimalist design inspired by vintage hardware. SYNTOPHONE PRO (subscription): Upgrade to unlock the full studio: • Premium Waveforms: Sine, Sawtooth, and Triangle. • Studio Effects: high-quality Reverb and Delay. • Pro Sound Panel: a second detuned oscillator for a fatter analog tone, hands-on delay time & feedback controls, and live MIDI output — play GarageBand and other synth apps as a virtual MIDI keyboard. • 12 more built-in songs to learn. • MIDI Export: save and share your recordings as .mid files. WHY SYNTOPHONE? No setup, no menus to fight — open the app and make music immediately. Then, when you're ready, it becomes a plug-in in your studio. Note: The app includes an auto-renewable subscription (Syntophone Pro) for premium features. For Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Screenshots
Verdict
The clearest difference is rating: Retro Synth at 4.2 against Core Synth HD's 3.4. Core Synth HD's advantage is iOS requirement (8.0 vs 17.0). 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 HD sells 1 one-off in-app purchase and Retro Synth sells 3 in-app purchases, starting at $3.99 per month. Whichever you choose, the download price is not the number that matters.
Retro Synth holds the better App Store score, 4.2 against 3.4. Both are backed by a comparable volume of ratings — 5 and 5 respectively.
Core Synth HD ships an update every 4 months, Retro Synth every 2 months. The most recent releases landed on October 20, 2026 and October 17, 2026 respectively.
| Parameter | Core Synth HD | Retro Synth |
|---|---|---|
| Price | Free | Free |
| Rating | 3.4 (5 ratings) | 4.2 (5 ratings) — better |
| Positive reviews | 30.6% of reviews | — |
| Number of ratings | 5 | 5 |
| Update frequency | Every 4 months | Every 2 months — better |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Devices | iPad | iPhone, iPad — better |
| Requires iOS | 8.0 — better | 17.0 |
| Further details — not scored | ||
| Size | 10 MB | 14 MB |
| Age rating | 4+ | 4+ |
| Developer | Core Engine Apps | Kerem ERSU |
Customer experience
Core Synth HD
Retro Synth
Bugs and requests
Core Synth HD
Reported bugs
21 issues- No sound on iPad Pro
- No sound on iOS 12
- No sound since last update
- Program doesn't start after update
- Ad blocks view
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- App crashes on load
- App crashed frequently
- Rarely produced sound
- Annoying clicking noise when playing a note
- Stopped playing notes after a while
- App reset to free module after purchase
- Lost saved presets after update
- CS doesn't work after iOS6 update
- Sound quit working suddenly
- No sound after purchase
- No audio on iPad 2
- Keyboard stops making noise after playing
- Crashes on every load
- Clipping pops and clicks
- Audible clicks between notes
- Constant click with the sounds
Requested features
17 requests- Add MIDI support
- Add Audiobus support
- Add recording with copy/paste
- Add sine wave for sub basses
- Add polyphony option
Show 12 moreShow fewer
- Add tempo sync delay, flange, chorus
- Add bit reduction
- Fix modulation clipping
- Fix clicking/popping sounds
- Add manual
- Add more presets
- Add noise generator
- Add detuning on both oscillators
- Add ability to map LFO to mod wheel
- Add switch to turn arpeggiator on/off
- Add Core Midi and MIDI over wifi support
- Fix Osc Octave Text numbering
Retro Synth
Not enough reviews yet to summarise bugs or requests.
In-app purchases
Core Synth HD
- Full Version Upgrade$1.99
Retro Synth
- Monthly Subscription$3.991 Month
- Annual Subscription$24.991 Year
- Remove ads$2.99








