MIDIWriter vs BlueKeyDetect
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
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.
- 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
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[[ 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
BlueKeyDetect
Instantly identify the musical key and tempo of songs by recording short audio clips. Ideal for musicians in jam sessions needing quick key information.
- Record audio clips
- Detect musical key
- Display beats per minute (BPM)
- Supports guitar and bass jam sessions
- Multiple recording options for accuracy
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If you are part of a jam sessions with guitar or bass, you should know the key in which the others are playing. The pros among you may be able to hear that, but I either need the information from the chord sheet or someone knows the key ... As a programmer, I quickly have an app in mind simply recording a piece of a song and then recognizing the key via my iPhone. The result is the BlueKeyDetect app: One touch on the display plus a short piece of recording and the beats per minute with the key of the song are displayed. You should record short pieces several times or a slightly longer one to get the correct key displayed. There are limits, since the key in the song can also change and depending on the song, the recognition can be difficult anyway, but in practice it still works quite well if you take a few things into account: ① Find places in the song where there is a lot of sound. Drums and percussion don't do much to recognize the key. ② The longer you record the song, the greater the chances of recognizing the correct key. Alternatively, you can record short phrases several times and then choose the most detected key. ③ Background noise makes detection difficult, so if possible record only the song and not at a low level.
Screenshots
Verdict
The clearest difference is rating: BlueKeyDetect at 5.0 against MIDIWriter's 1.5. BlueKeyDetect also leads on update cadence (every 8 months vs every 35 months) and iOS requirement (10.0 vs 16.0). On price, ratings volume, ads and in-app purchases 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
MIDIWriter costs $0.99 and BlueKeyDetect $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.
BlueKeyDetect holds the better App Store score, 5.0 against 1.5. Both are backed by a comparable volume of ratings — 2 and 1 respectively.
MIDIWriter ships an update every 35 months, BlueKeyDetect every 8 months. The most recent releases landed on October 18, 2026 and October 13, 2026 respectively.
| Parameter | MIDIWriter | BlueKeyDetect |
|---|---|---|
| Price | $0.99 | $0.99 |
| Rating | 1.5 (2 ratings) | 5.0 (1 ratings) — better |
| Positive reviews | 0.0% of reviews | — |
| Number of ratings | 2 — better | 1 |
| Update frequency | Every 35 months | Every 8 months — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Paid |
| Devices | iPhone, iPad | iPhone, iPad, iPod — better |
| Requires iOS | 16.0 | 10.0 — better |
| Further details — not scored | ||
| Size | 31 MB | 15 MB |
| Age rating | 4+ | 4+ |
| Developer | Masayuki Akamatsu | Stefan Arnhold |
Customer experience
MIDIWriter
BlueKeyDetect
In-app purchases
MIDIWriter
No in-app purchases
BlueKeyDetect
No in-app purchases
Questions
Is MIDIWriter free?
Is BlueKeyDetect free?
Which has better reviews, MIDIWriter or BlueKeyDetect?
Do MIDIWriter or BlueKeyDetect have ads?
Which is updated more often, MIDIWriter or BlueKeyDetect?
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