Midiflow vs KeyStage Lite
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Midiflow
This app enables seamless MIDI data transfer between different applications on your device. It allows for app synchronization, routing MIDI from sequencers to synths, and assigning keyboard zones. Users can save and recall configurations, and monitor MIDI activity.
- App-to-app MIDI routing
- MIDI clock synchronization
- Channel filtering and remapping
- Note and velocity manipulation
- Custom virtual MIDI ports
- Preset saving and recall
- Controller filtering and remapping (in-app purchase)
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Midiflow allows you to send MIDI from app to app in a similar way to what you already do with audio. That way, you can sync apps with each other or send MIDI parts from a sequencer app to different synth apps. You can also route the MIDI from your keyboard to apps and assign different key zones to them. Different settings can be stored as a preset, recalled later and inserted into another preset. Furthermore, all MIDI transfer can be monitored in order to find problems or just to learn what MIDI is doing (normally) behind the scenes. Important news: There is a full documentation on the Midiflow website now! HOW DOES IT WORK? Midiflow allows you to create multiple routings. Each routing receives MIDI data on its source and sends it to its destination. The selectable sources and destinations include your CoreMIDI compatible MIDI interface and other apps if they provide a virtual MIDI port. You can also create custom ports that can be used by other apps to receive data from Midiflow or send data to it. A routing also has a modifier which allows you to filter data or modify it. That way, you can transpose notes, limit them to a key range, change the MIDI channel of the incoming data, etc. (see the feature list below). LIST OF FEATURES + MIDI clock – specify tempo and your apps will be in sync + Channel filtering and remapping + Velocity filtering – a routing is only active for notes in a given velocity range + Note shift – shift all notes by a given number of half-tone steps + Note remapping – shift each note individually + Velocity remapping – apply a velocity curve, transform to fixed velocity, or specify the map value by value. In the latter case, you can also export the mapping to the clipboard, edit it in another app like Apple Numbers, and paste it back in Midiflow + Filtering out Clock or dividing the tempo into subdivisions + Filtering out SysEx + Connect to other iPads/iPhones via Bluetooth MIDI (iOS8 or higher) + Save a configuration as a preset, which can be recalled later or inserted into another preset + Custom virtual MIDI ports, which can be selected in other apps as a source or destination + Control aspects of Midiflow via MIDI. For example, select presets or control the clock with any MIDI command + Launch your synth apps from Midiflow (works with an increasing number of apps) + Sharing your configurations ADDITIONAL FEATURES (available as an In-app purchase) + Filtering and remapping of controllers – transform (a) the controller type, e.g. from CC1 to pitch-bend or note value to CC1, and (b) transform the value in several ways: as a linear remapping from an input range to an output range, as a curve, or as a value by value list. In the latter case, you can also export the mapping to the clipboard, edit it in another app like Apple Numbers, and paste it back in Midiflow. This allows you to create very sophisticated remappings. + Controller conditions – adjust your routings depending on other MIDI messages. This allows you to create sophisticated behavior within your setup by switching routings on and off. DOES MIDIFLOW WORK WITH MY SYNTH APPS? Midiflow works with every app that has a correct MIDI implementation. In the best case, it has an own virtual MIDI port and can be configured so that it receives MIDI only on that port. Unfortunately, some apps don't have that, but can at least be restricted to one MIDI channel. In that case, you can send to that channel on the global MIDI port "Network Session 1". If you can't select a channel either, then the app won't work with Midiflow. There is a tutorial video on www.midiflow.com that explains this in more detail.
KeyStage Lite
This app acts as a master controller and audio mixer for keyboard players. It allows simultaneous control of multiple hardware and software instruments using various MIDI controllers. Organize songs into sections, customize instrument sounds, and manage MIDI mappings with advanced scripting capabilities.
- Control multiple MIDI controllers and instruments
- Host AUv3 instruments and effects
- Create complex keyboard splits and layers
- Advanced MIDI mapping and scripting
- Audio mixer with track control
- Play and manage audio files
- View PDF and JPG files
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KeyStage is a master controller, AUv3 host, and audio mixer app designed mainly for keyboard players. With KeyStage, you can simultaneously control any number of hardware and software instruments using any number of MIDI controllers in an organized way. Each project consists of sections (which corresponds to sections of a song). In each section you can change sounds and sound parameters of connected instruments, create complex splits and layers of your keyboard(s), change the functionalities of sliders/knobs/pedals of your MIDI controllers by creating advanced MIDI mappings, write your own scripts, view PDF and JPG files (e.g. sheet music) and lyrics, and much more. LIST OF FEATURES • Connect any number of MIDI controller to any number of MIDI instruments by creating tracks. • Load AUv3 instruments, effects, and MIDI Processors. • Assign any region of your keyboard(s) to any connected instrument. • Change velocity curve and velocity limits, and create velocity splits and layers. • Transpose notes and restrict notes to any key using pitch shifter. • Create mixer units to combine audio signals, turning KeyStage into an audio mixer. • With the player units, you can play wav, mp3, and m4a files, add marker points, automate actions (like play, stop, move to a marker etc.) using custom translators, or trigger certain events (like changing sections) when the player reaches a certain marker. • Input units allows you to use the microphone input, or the hardware inputs of a connected audio interface. • The Main Mixer view allows you to control volume levels and pans of all tracks, connect effect units, and connect units to mixer units. • Create instrument presets to easily change sounds of instruments by choosing patch names from patch lists. • KeyStage can also import Cubase Patch Scripts to automatically create instrument presets for your MIDI instruments. • KeyStage automatically detects new MIDI connections and recommends matching instrument presets from a database. • Simulate auto-sustain on any connected instrument. • KeyStage has a multi-track recorder, which lets you record any number of tracks simultaneously. • Change or filter any MIDI signal using custom translators. Use “Relative Control” switch to smoothly change the parameters of your instruments without any jumps. • Use XY control unit to send control change and pitch bend messages to any connected MIDI instrument. • Create setlists, quick access all the songs in a setlist from a setlist bar, move to previous/next songs from live console or using external MIDI. • Create virtual MIDI inputs/outputs for KeyStage. • Use virtual MIDI piano controller to play connected instruments. • View PDF and JPG files. Link any page or region of any file to any section. • Backup and restore your songs and global properties to Dropbox. • Map special actions (like changing octaves, switching sections, changing pages of a PDF file) to notes and controllers using custom translators. • You can write your own scripts in custom translators, which opens up endless possibilities. • Use MPE routing to control any MIDI instrument using MPE controllers like Seaboard. Use custom translators to change the functionalities of each MPE dimension. • KeyStage supports smooth transitions between sections. Pressed notes will continue to sound when you switch sections. You can access demo videos and video tutorials on my Youtube channel.
Screenshots
Verdict
The clearest difference is price: KeyStage Lite at Free against Midiflow's $7.99. KeyStage Lite also leads on in-app purchases (none vs 3). Midiflow's advantage is update cadence (every 5 weeks vs every 3 months) and ratings volume (39 vs 7). On rating, review sentiment 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
KeyStage Lite is free to download; Midiflow costs $7.99 up front. Midiflow sells 3 one-off in-app purchases. KeyStage Lite asks for nothing beyond the download.
On the App Store both sit at effectively the same score — 4.0 for Midiflow against 4.0 for KeyStage Lite. That said, the two scores are not equally well evidenced: Midiflow has 39 ratings behind it against 7, so its average is the more settled of the two. Written reviews are what separate them: 59% of Midiflow's written reviews are positive against 60% of KeyStage Lite's.
Midiflow ships an update every 5 weeks, KeyStage Lite every 3 months. The most recent releases landed on October 12, 2026 and October 7, 2026 respectively.
| Parameter | Midiflow | KeyStage Lite |
|---|---|---|
| Price | $7.99 | Free — better |
| Rating | 4.0 (39 ratings) | 4.0 (7 ratings) |
| Positive reviews | 58.8% of reviews | 60.0% of reviews — better |
| Number of ratings | 39 — better | 7 |
| Update frequency | Every 5 weeks — better | Every 3 months |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases | Free — better |
| Devices | iPhone, iPad, iPod — better | iPad |
| Requires iOS | 9.0 — better | 13.0 |
| Further details — not scored | ||
| Size | 4 MB | 61 MB |
| Age rating | 4+ | 4+ |
| Developer | Johannes Doerr | Ali Gokturk |
Customer experience
Midiflow
KeyStage Lite
Bugs and requests
Midiflow
Reported bugs
45 issues- Frequent crashes while editing CC map
- Mapped CCs dropped during performance
- App does not open on iOS 10
- Layout issues on iPhone 11 (no 'Done' button)
- App stops working, opens for 2 seconds then closes
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- Bug in Velocity remapping: 'Reset curve' makes screen blank
- Note Off messages have vel value = 0
- App simply doesn't start after paid updates
- No 'Done' or 'Back' button visible in menus
- App crashes when editing a song and saving
- Edits lost after crash
- Backup song lost after crash
- App crashes when trying to remap
- App crashes on first note when Roli Seaboard is connected
- App closes when searching for nearby devices
- App closes when selecting 'find nearby devices' or 'advertise device'
- App doesn't work with iOS 14
- App doesn't work with iOS 15
- App doesn't work with iOS 16
- App crashes on iPad 5 after update
- App closes immediately after starting
- No back or cancel button, stuck in menus
- CC control mapping issues (e.g., CC7 dropped)
- Bluetooth connectivity crashes the app
- Program Change to MIDI note remapping not working
- App doesn't search for nearby devices
- App force closes when remapping
- GUI problems with returning to main page
- App crashes on first note
- App doesn't load after paid updates
- No return button
- Layout issues on iPhone
- Filter out Note Off messages functionality missing
- Frequent crashes while editing
- Mapped CCs dropped during performance
- Note off velocities are ignored
- App doesn't open
- App closes immediately
- App doesn't work with SampleTank in background
- Remapping doesn't work properly
- MIDI messages blocked or morphed
- Remapping adds code instead of replacing
- Fixed MIDI channels in Korg iPolysix
- Does not work with Arturia iMini/iProphet
- App shutdown on iPad 2
Requested features
6 requests- AUv3 plugin version
- Mass sharing of songs
- Dark mode
- Ability to map multiple notes from one key press
- Individual transpose for split zones
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- More MIDI features controllable by external hardware
KeyStage Lite
Not enough reviews yet to summarise bugs or requests.
In-app purchases
Midiflow
- Send Controller On Load$1.99
- Controller Conditions$2.99
- Controller Remapping$3.99
KeyStage Lite
No in-app purchases








