Comparison

MIDIWriter vs FET Acoustic Compressor

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

Head to head
About

MIDIWriter

This app transforms keyboard input into musical notes and sounds. Type characters to instantly generate MIDI messages, or input phrases to create musical sequences with adjustable tempo and looping. It includes a built-in sound engine and supports external MIDI devices and apps.

Highlights
  • Text to MIDI conversion
  • Built-in General MIDI sound engine
  • Phrase playback with tempo control
  • Drum mode with multiple kits
  • External MIDI output
  • Hardware keyboard support
  • Wi-Fi MIDI networking
Features
Read full description

[[ A STRANGE MUSIC TOOL FOR MANIAC MUSIC LOVERS! ]] MIDIWriter is a unique app that converts keyboard input into MIDI note messages. Each character you type instantly produces sound. You can also enter a phrase and play it back as a sequence with adjustable tempo and loop options. KEY FEATURES: Built-in Sound Engine: No external app required! MIDIWriter includes a built-in General MIDI sound engine with 128 instruments and 9 drum kits. Just type and hear the sound immediately. Phrase Playback: Enter any text and play it as a musical sequence. Adjust the tempo (1-480 BPM), enable loop mode, and let your words become music. Space characters can be used as rests. Drum Mode: Switch to drum mode to play percussion sounds. Choose from 9 GM drum kits including Standard, Room, Power, Electronic, 808/909, Jazz, Brush, and Orchestral. MIDI Output: Send MIDI to other apps or external devices. Configure MIDI channel (1-16), program change (0-127), and destination. Works with Virtual MIDI and MIDI Network Session. Can be used simultaneously with the built-in sound engine. Keyboard Support: Use the on-screen software keyboard, or connect a Bluetooth/USB hardware keyboard for a real typing experience. Supports Japanese input with proper IME handling. MIDI Network Session: Connect to Mac or other iOS devices over Wi-Fi to control CoreMIDI-compatible sound generators remotely. Dark Mode & Rotation: Full support for light and dark modes. Works in portrait and landscape orientations on both iPhone and iPad. Note: Playback stops when the app goes to background. Using the Built-in Sound: Simply launch MIDIWriter and start typing. Each key produces a unique sound based on its character code. Enable drum mode in Settings for percussion sounds. Using with External MIDI Apps (Virtual MIDI): 1. Open a CoreMIDI sound generator app. 2. In MIDIWriter Settings, turn on "MIDI Output" and select the destination. 3. Type any key to hear sound from the external app. Using with Mac (MIDI Network Session): 1. Connect iPhone and Mac to the same Wi-Fi network. 2. Open MIDIWriter on iPhone. 3. On Mac, open "Audio MIDI Setup" and configure Network MIDI. 4. Connect your iPhone to the session. 5. Open a CoreMIDI app on Mac and select the network session as MIDI input. 6. Type on MIDIWriter to play sounds on Mac. Credits: Built-in sound engine uses "GeneralUser GS" SoundFont by S. Christian Collins. https://schristiancollins.com/generaluser.php

About

FET Acoustic Compressor

This app emulates the warm, musical character of classic FET compressors for acoustic instruments and more. It offers intuitive controls for punch, presence, and glue, with a special "All-In" mode for aggressive sounds. Designed for mobile studios and live performance.

Highlights
  • Classic FET compression emulation
  • Voiced for acoustic guitar, versatile for other instruments
  • Intuitive controls: IN, ATTACK, RELEASE, RATIO, OUT, DRY, SC HPF
  • Special "All-In" mode for aggressive sounds
  • AUv3 plugin support for popular DAWs
  • Low latency for live performance
  • Factory presets included
Read full description

FET Acoustic Compressor brings the warm, musical character of classic FET compression — voiced in the tradition of the Cali76 by Origin Effects and the vintage 1176 circuit it's based on — to your iPhone and iPad. Dialed in for acoustic guitar, but equally at home on electric guitar, bass, vocals, keys, or any source that benefits from that signature FET feel. Whether you're tracking at home, mixing in a DAW, or running signal live through Loopy Pro or AUM, FET Acoustic Compressor gives your sound the punch, presence, and glue it needs. Voiced for feel The compression curve, soft knee, and gentle FET saturation are tuned for the transients and dynamics of acoustic strings — but that voicing translates beautifully to any instrument that needs a compressor with character. It sits, it glues, it breathes. Full control, intuitive layout - IN — Drive the input and push into compression - ATTACK / RELEASE — Fast enough to catch a pick attack; slow enough to let the body bloom - RATIO — 2:1 to 20:1 for everything from gentle leveling to heavy squash - OUT — Trim your output level - DRY — Blend in parallel compression for the best of both worlds - SC HPF — High-pass the sidechain so low-end doesn't trick the detector - Gain Reduction Meter — See exactly what's happening in real time All-In mode Tap the RATIO label to activate All-In — the infamous "all buttons simultaneously" trick from vintage 1176-style compressors. Ratio jumps to 100:1, the knee tightens, and asymmetric FET saturation adds the gritty, pumping character that's made this mode a go-to for aggressive sounds. A secret weapon hiding in plain sight. Factory presets to get you started - Compressed Fingerstyle - Dynamic Fingerstyle - Pop Strumming Built for the mobile studio and stage - AUv3 plugin — use in GarageBand, AUM, Loopy Pro, Cubasis, and any AUv3 host - Low latency — optimized for live performance and real-time processing - 4x oversampled processing for clean, artifact-free compression - Designed for iPhone and iPad *Cali76 is a trademark of Origin Effects Ltd. 1176 and UREI are trademarks of their respective owners. GarageBand is a trademark of Apple Inc. AUM is a product of Kymatica AB. Loopy Pro is a product of A Tasty Pixel. FET Acoustic Compressor is not affiliated with, endorsed by, or sponsored by any of the above companies.*

Screenshots

MIDIWriter4 screens
FET Acoustic Compressor1 screens

Verdict

The call

The clearest difference is review sentiment: FET Acoustic Compressor at 100% against MIDIWriter's 0%. FET Acoustic Compressor also leads on rating (5.0 vs 1.5) and update cadence (every 2 months vs every 35 months). MIDIWriter's advantage is price ($0.99 vs $5.99). 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

CostPrice · In-app purchases · Ads · Monetization

MIDIWriter costs $0.99 and FET Acoustic Compressor $5.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

FET Acoustic Compressor holds the better App Store score, 5.0 against 1.5. Both are backed by a comparable volume of ratings — 2 and 2 respectively. Written reviews point the same way: 0% of MIDIWriter's written reviews are positive against 100% of FET Acoustic Compressor's.

UpkeepUpdate frequency

MIDIWriter ships an update every 35 months, FET Acoustic Compressor every 2 months. The most recent releases landed on November 1, 2026 and October 31, 2026 respectively.

Scorecard5 real differences · 5 level
MIDIWriter versus FET Acoustic Compressor: the parameters behind the verdict, then further details
ParameterMIDIWriterFET Acoustic Compressor
Price$0.99 — better$5.99
Rating1.5 (2 ratings)5.0 (2 ratings) — better
Positive reviews0.0% of reviews100.0% of reviews — better
Number of ratings22
Update frequencyEvery 35 monthsEvery 2 months — better
AdsNoNo
In-app purchasesNoNo
MonetizationPaidPaid
DevicesiPhone, iPadiPhone, iPad, iPod — better
Requires iOS16.013.0 — better
Further details — not scored
Size31 MB9 MB
Age rating4+4+
DeveloperMasayuki AkamatsuShelbybark LLC

Customer experience

MIDIWriter

All ratings2 ratings
Positive0.0%
Neutral0.0%
Negative100.0%
Written reviews4 reviews
Positive0.0%
Neutral0.0%
Negative100.0%

FET Acoustic Compressor

All ratings2 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

MIDIWriter

No in-app purchases

None

FET Acoustic Compressor

No in-app purchases

Questions

Is MIDIWriter free?
MIDIWriter costs $0.99, with no in-app purchases.
Is FET Acoustic Compressor free?
FET Acoustic Compressor costs $5.99, with no in-app purchases.
Which has better reviews, MIDIWriter or FET Acoustic Compressor?
FET Acoustic Compressor is rated higher. MIDIWriter averages 1.5 out of 5 from 2 ratings, while FET Acoustic Compressor averages 5.0 from 2 ratings.
Do MIDIWriter or FET Acoustic Compressor have ads?
Neither MIDIWriter nor FET Acoustic Compressor shows ads.
Which is updated more often, MIDIWriter or FET Acoustic Compressor?
MIDIWriter ships an update every 35 months, and FET Acoustic Compressor every 2 months. Most recently, MIDIWriter was updated on November 1, 2026 and FET Acoustic Compressor on October 31, 2026.

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