MIDIWriter

Name: MIDIWriter
Price: 0.99 USD
Rating: 1.5 (2 reviews)
Author: Masayuki Akamatsu

By: Masayuki Akamatsu App

Turn Text into MIDI/Sound Tool

Overview

Version:

2.0.1

Last updated: 2026-07-04

Ranking

#939,223 ▲ 180

Overall

Features & Capabilities

[[ 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):

Open a CoreMIDI sound generator app.
In MIDIWriter Settings, turn on "MIDI Output" and select the destination.
Type any key to hear sound from the external app.

Using with Mac (MIDI Network Session):

Connect iPhone and Mac to the same Wi-Fi network.
Open MIDIWriter on iPhone.
On Mac, open "Audio MIDI Setup" and configure Network MIDI.
Connect your iPhone to the session.
Open a CoreMIDI app on Mac and select the network session as MIDI input.
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

User Growth & Download Statistics

App

By:

Masayuki Akamatsu

Rating:

1.50

(2)

Version:

2.0.1 Last updated: 2026-07-04

Version code:

887815258

Creation date:

2012-04-25

Compatible devices:

Size:

30.57MB

Price:

0.99

URLs:

Full description:

Source:

Apple Apps Store

Data ingested on:

2026-09-04

Compare stats and ranking:

Ranking

# 939,223 ▲ 180

For Developers

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Contact the developer

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Developed by:

Masayuki Akamatsu

Apple Apps Store

https://apps.apple.com/us/app/midiwriter/id520751563

User Reviews

This is a great idea, and it could be very useful if it worked better and was recognized by more music apps, like AUM. My MIDI keyboard has a limited number of buttons and other controls on it, so this would be useful for sending program change and other MIDI messages. The description says the last support for this thing was 4 years ago. Another reviewer said it looks like it was put up here and then forgotten; I agree. It’s too bad; this app is a good idea that didn’t pan out...

by Gt*****, 2019-07-02

A buck isn't much money, but I don't think I got a dollar's worth of pleasure out of this. There's no way of knowing what note will get played when a key is depressed, and no way to specify or control that. Also, the app starts in a mode in which each key typed produces a note (again, you get no control of the note's duration), but if keyboard focus is ever once given to the text field, you're stuck in a "batch" mode from then on, and can't get back to the key-by-key mode. It's sort of a pity, because — viewed as a proof of concept exercise — it's actually a potentially interesting idea, and might allow the use of an external bluetooth keyboard (for instance) to quickly audition the sounds of a MIDI synthesizer, without either setting up any external MIDI hardware, nor using the on-screen keyboard within the synthesizer app. As it is, it seems that the developer just got something more-or-less working, and then "threw it out there" to see if anybody would pay for it. Well, I did pay for it, but would encourage you not to. To summarize, it's not all that much fun to play with after the first 20 seconds or so, when it's been established that typing a key can, in fact, cause a sound to be played. And although the fun value is limited, the app's use for more than that is non-existant.