Comparison

Caustic vs AudioKit Retro Piano

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

Head to head
About

Caustic

Create music with a virtual synthesizer and sampler rig. Build your sound by adding up to 14 machines, including synths and drum machines. Features a mixer, effects, and a song sequencer for real-time audio production.

Highlights
  • Virtual analog subtractive synthesizer
  • Multi-sample wave synthesizer
  • Sampling drum machine
  • Effects rack with 20 effect types
  • Mixer desk with EQ and effects
  • Song sequencer
  • AudioBus and AudioCopy/Paste support
Features
Read full description

Caustic 3 is a music creation tool inspired by rack-mount synthesizer/sampler rigs. Everything is real-time and optimized for mobile devices. Create your rack by adding up to 14 machines from a choice of: * Subsynth - Virtual analog subtractive synthesizer * PCMSynth - Multi-sample wave synthesizer * BassLine - 303-like monosynth * BeatBox - 8-channel sampling drum machine * PadSynth - Harmonic table pad synthesizer * 8BitSynth - 8bit equation solver synthesizer * Modular - Fully configurable and routable synthesizer * Organ - Tonewheel organ with rotary speaker * Vocoder - 8-band harmonic vocoder * FMSynth - DX-style 3-operator fm synthesizer * KSSynth - Karplus-Strong string modeling synthesizer * SawSynth - Supersaw-type synthesizer The app also includes: * Effects rack supporting 2 effects per machine (20 effect types). * Mixer desk with EQ, panning and global Delay/Reverb effects. * Master section with effect slots, parametric EQ and limiter. * Song sequencer AudioBus support for Input and Output slots. AudioCopy Paste + AudioShare support for import and export. Supports automation recording on most controls and includes powerful editors for modifying automation curves. Users can record their own WAV files for use in the PCMSynth, BeatBox, and Vocoder or import files through iTunes file sharing, ACP, AudioShare, or the built-in FTP server. Supports all uncompressed WAV files (8-16-24-32bit, any sampling rate). The PCMSynth can also load SoundFont files (.sf2), SFZ and FL/Xewton instruments (.instr, .ZIP) "Open In.." import support for all preset types, .WAV, .SF2 and .MID. (MIDI (.mid) files can be imported as raw sequencer note data.) Supports CoreMIDI and virtual MIDI for note, velocity and CC data. (be sure to set "Enable background audio" in advanced options to use virtual MIDI) See the in-app help section for dozens of informative tutorial videos and full online manual. There is also a FREE (full version) PC/Mac version available for download on the product website. Come visit www.singlecellsoftware.com to download more presets, request features, share your tracks and hear what others are creating with Caustic 3. Works on iPhone/iPod but iPad is recommended.

About

AudioKit Retro Piano

Create vintage and modern piano sounds with this synthesizer app. It offers lo-fi effects, custom vinyl noise, and a stacked synth for unique vibes. Express yourself with simple controls and a big sound in a small package.

Highlights
  • Lo-fi and modern piano sounds
  • Custom vinyl noise and crush effects
  • Stacked vintage synth pads
  • Standalone app and AUv3 plugin
  • MIDI keyboard support
  • Universal iPhone & iPad app
Features
Read full description

Super beautiful vintage piano. This wonderful Piano can sound Lo-Fi or modern and clean. Sounds great in a mix, or used alone. ++ You can even use it with a MIDI Keyboard or iOS host. ++ Big Piano Sound, small size! The entire app is under 70mb on most devices. Perfect for pro sound on the go! "Love the way it sounds… Vinyl noise and crush, Dope!" – Circuit Brent, 12-Bit Soul Express yourself. Create your signature retro piano sound. Simple controls allow you to create an emotional vibe for your music. Big sound, small space! 500mb of samples compressed to 50mb for space-saving expressive keys. Plus custom Vinyl noise to give it a "Sampled" sound. PLUS, we stacked the piano with a vintage synth for a perfect pairing of piano and synth pads. Creates retro feelings, vibes, and sounds. Easily make lo-fi and nostalgic sounds! FEATURES: + Includes both iPhone & iPad version for one low price! + Standalone app & AUv3 Plug-in + Vinyl Record warble speed & depth + Universal: Get both iPhone & iPad versions for life, free + Multiple velocities: Use an external MIDI piano keyboard for expressive sounds + 40+ Original Vinyl Noise samples + Crush, Distortion, and special sauce + Tremolo, Reverb, and other cool FX! + Works great as an AU plugin in GarageBand, Cubasis 3, BM3, NS2, AUM, Auria Pro, and more + Oh yeah, it sounds really, really good! This app is can be dirty, distorted, noisy and lo-fi sounding piano! Subscribe to access to premium app features; subscription details are the following: - Length: weekly or yearly - Free trial: only on selected subscriptions - Your payment will be charged to your iTunes Account as soon as you confirm your purchase - You can manage your subscriptions and turn off auto-renewal from your Account Settings after the purchase - Your subscription will renew automatically, unless you turn off auto-renew at least 24 hours before the end of the current period - The cost of renewal will be charged to your account in the 24 hours prior to the end of the current period - When canceling a subscription, your subscription will stay active until the end of the period. Auto-renewal will be disabled, but the current subscription will not be refunded - Any unused portion of a free trial period, if offered, will be forfeited when purchasing a subscription Terms & Conditions: [https://magic-cake-e95.notion.site/AudioKit-Retro-Piano-Terms-Conditions-150cf6557a0880cd9ce8d0cbf30b44e8?pvs=4](https://www.notion.so/AudioKit-Retro-Piano-Terms-Conditions-150cf6557a0880cd9ce8d0cbf30b44e8?pvs=21) Privacy Policy: [https://magic-cake-e95.notion.site/AudioKit-Retro-Piano-Privacy-Policy-150cf6557a0880b0a559e2fd23f56d4a?pvs=4](https://www.notion.so/AudioKit-Retro-Piano-Privacy-Policy-150cf6557a0880b0a559e2fd23f56d4a?pvs=21) NOTE: This app has no official affiliation with AudioKit Pro, LLC. It was built using the free AudioKit source code.

Screenshots

Caustic4 screens
AudioKit Retro Piano4 screens

Verdict

The call

The clearest difference is price: AudioKit Retro Piano at Free against Caustic's $9.99. AudioKit Retro Piano also leads on rating (4.3 vs 3.6) and update cadence (every 5 weeks vs every 4 months). Caustic's advantage is in-app purchases (none vs 4) and ads (none vs shown). On ratings volume 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

CostPrice · In-app purchases · Ads · Monetization

AudioKit Retro Piano is free to download; Caustic costs $9.99 up front. AudioKit Retro Piano sells 4 in-app purchases, starting at $2.99 per 7 days. Caustic asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

AudioKit Retro Piano holds the better App Store score, 4.3 against 3.6. Both are backed by a comparable volume of ratings — 179 and 158 respectively. Written reviews point the same way: 58% of Caustic's written reviews are positive against 68% of AudioKit Retro Piano's.

UpkeepUpdate frequency

Caustic ships an update every 4 months, AudioKit Retro Piano every 5 weeks. The most recent releases landed on November 1, 2026 and November 3, 2026 respectively.

Scorecard8 real differences · 2 level
Caustic versus AudioKit Retro Piano: the parameters behind the verdict, then further details
ParameterCausticAudioKit Retro Piano
Price$9.99Free — better
Rating3.6 (179 ratings)4.3 (158 ratings) — better
Positive reviews57.8% of reviews68.1% of reviews — better
Number of ratings179 — better158
Update frequencyEvery 4 monthsEvery 5 weeks — better
AdsNo — betterYes
In-app purchasesNo — betterYes
MonetizationPaidFree with in-app purchases — better
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS7.0 — better13.0
Further details — not scored
Size52 MB109 MB
Age rating4+4+
DeveloperRejean PoirierAudiobus Pty Ltd

Customer experience

Caustic

All ratings176 ratings
Positive60.2%
Neutral8.5%
Negative31.3%
Written reviews218 reviews
Positive57.8%
Neutral7.8%
Negative34.4%

AudioKit Retro Piano

All ratings158 ratings
Positive80.4%
Neutral3.8%
Negative15.8%
Written reviews91 reviews
Positive68.1%
Neutral12.1%
Negative19.8%

User reviews

Caustic

From 179 App Store ratings

What we love

  • 🚀 Powerful and feature-rich
  • 👍 Intuitive workflow
  • 🎨 Excellent sound quality
  • 💸 Great value for money

Room to improve

  • 🐛 Compatibility issues with newer iOS versions
  • 🔇 No Bluetooth audio support
  • 📁 Difficulty accessing/exporting files
  • 🔧 Needs more updates and bug fixes

AudioKit Retro Piano

From 158 App Store ratings

What we love

  • 🎵 Beautiful, warm, and rich piano sounds
  • ✨ Excellent presets with creative variety
  • 🎛️ Simple and intuitive interface
  • 🆓 Free or affordable pricing (original release)
  • 🔌 AUv3 audio unit support

Room to improve

  • 💰 Changed to subscription model ($2.99/month)
  • 🔒 Added user tracking/spyware concerns
  • 🌐 Now requires internet connection
  • 🐛 Frequent crashes and instability
  • 🔊 Audio clipping and distortion issues

Bugs and requests

Caustic

Reported bugs

3 issues
  • Crashes and freezes on newer iPhones
  • Interface scaling problems on larger screens
  • Unresponsive controls in certain scenarios

Requested features

4 requests
  • Bluetooth audio support
  • Improved file management and export options
  • More synth/instrument options
  • Expanded effects and mixing capabilities

AudioKit Retro Piano

Reported bugs

13 issues
  • Infinite loading screen on startup
  • Crashes when used as AU in GarageBand and other DAWs
  • MIDI keyboard input not recognized
  • Audio unit extension not appearing in DAW options
  • Presets revert to default when project reopens
Show 8 more
  • Note drops while playing with MIDI controller
  • Constant audio clipping and crackling
  • DSP fluctuations in AUM (15-65%+)
  • App freezes after iOS 14+ updates
  • Vinyl noise sound only (missing piano sound)
  • Incompatible with Keystep and Keylab 61
  • Controls inaccessible on iPhone SE
  • App crashes unexpectedly in Nano Studio

Requested features

9 requests
  • Attack time control
  • Stretch/microtuning options
  • Sequencer and arpeggiator integration
  • Built-in recording functionality
  • Proper state saving in DAWs
Show 4 more
  • Rhodes piano simulation
  • Prevent device sleep during MIDI input
  • Better preset organization
  • Detailed changelog for updates

In-app purchases

None

Caustic

No in-app purchases

4 purchases

AudioKit Retro Piano

Subscriptions4
  • Weekly premium$2.997 Days
  • Weekly premium7 Days trial$2.997 Days
  • Yearly premium$9.991 Year
Show 1 more
  • Yearly premium7 Days trial$9.991 Year

Questions

Is Caustic free?
Caustic costs $9.99, with no in-app purchases.
Is AudioKit Retro Piano free?
AudioKit Retro Piano is free to download, with in-app purchases available.
Which has better reviews, Caustic or AudioKit Retro Piano?
AudioKit Retro Piano is rated higher. Caustic averages 3.6 out of 5 from 179 ratings, while AudioKit Retro Piano averages 4.3 from 158 ratings.
Do Caustic or AudioKit Retro Piano have ads?
AudioKit Retro Piano shows ads; Caustic does not.
Which is updated more often, Caustic or AudioKit Retro Piano?
Caustic ships an update every 4 months, and AudioKit Retro Piano every 5 weeks. Most recently, Caustic was updated on November 1, 2026 and AudioKit Retro Piano on November 3, 2026.

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