MIDI vs Callback Freeverb
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
MIDI
This app helps you discover, test, and troubleshoot MIDI devices like controllers and synths. It allows you to send specific MIDI commands and monitor incoming messages with timestamps for verification.
- Discover USB, Bluetooth, and RTP MIDI devices
- Send specific MIDI commands (Notes, CC, System Common, Real-Time)
- Monitor inbound MIDI with live, timestamped log
- Filter MIDI messages by command type
- Verify pitch bend and high-resolution CCs
- Test custom hardware and software MIDI implementations
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MIDIProbe is a pocket MIDI utility for iPhone and iPad that helps you discover, test, and troubleshoot MIDI devices (e.g., controllers, synths, mixers). Pick which endpoints to send to or listen to, fire off the exact MIDI commands you need, and watch a live, timestamped log to verify every message. • Discover USB, Bluetooth, and RTP network MIDI devices, and see detailed info like IDs, serial numbers, and transport type before selecting send/receive targets. - Send MIDI fast with interactive cards: - Notes, Control Change (CC), Program Change, Aftertouch, Pitch Bend; - System Common (Song Position Pointer, Song Select, Tune Request); - Real-Time (Start/Stop/Continue, Clock, Active Sensing, Reset); • Monitor inbound MIDI with a live log or grouped-by-command view, with filters for command types, clear controls, and timestamps. Typical use cases: • Reverse-engineer mixer control quickly: You have an X32 mixer and want to use a floorboard to mute/unmute channels. Connect both to MIDIProbe, discover the right endpoints, and watch which channel/CC/value combinations actually toggle mutes—then verify your floorboard sends the exact same messages before you risk it live. • Map a foot controller to a multi-FX unit: You want to configure a floorboard to switch presets/settings on your multi-effects processor. Use MIDIProbe to identify which Program Changes or CCs trigger the functions you need, then confirm the outgoing messages match your intended mapping. • Confirm keyboard controller channel routing: Check whether your keyboard is transmitting on the correct MIDI channel (or accidentally sending Omni), and verify splits/layers are hitting the channels your synth or app expects. • Validate DAW controller templates: Debug pad controller mappings for Ableton/Logic/Cubase—see exactly which notes/CCs each pad/knob/fader is sending, catch duplicated CC numbers, and confirm bank switching. • Troubleshoot “why doesn’t it respond?” fast: If your synth/module isn’t reacting, use MIDIProbe to confirm whether it’s receiving anything at all, whether the messages are on the wrong channel, or whether you’re sending the wrong command type. • Verify pitch bend and high-resolution CCs: Check pitch bend ranges and whether devices send 14-bit (MSB/LSB) pairs correctly for smooth parameter changes. • Build and test custom hardware/software: If you’re developing MIDI controller firmware or a MIDI iOS/macOS app, use MIDIProbe as your “known good” sender/receiver to test parsing, edge cases, and message timing. If you’re into this kind of thing, MIDIProbe is for you.
Callback Freeverb
This app offers a classic algorithmic reverb effect based on the Freeverb algorithm. It adds depth, space, and atmosphere to audio sources, creating lush, spacious ambience. Designed for mono use, it provides a smooth, musical reverb tail suitable for vocals and synthesizers.
- Classic Freeverb algorithm
- Schroeder/Moorer reverb topology
- Comb and allpass filters
- Mono operation
- Adds depth and space to audio
- Smooth, musical reverb tail
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A classic algorithmic reverb effect based on the Freeverb algorithm by Jezar at Dreampoint. A Freeverb-style Schroeder/Moorer reverb based on the classic 8-comb + 4-allpass topology, with simplified controls and no stereo spread. This reverb creates lush, spacious ambience through a network of comb and allpass filters. Freeverb is widely used in electronic music production, ambient music, and sound design to add depth, space, and atmosphere to audio sources. The algorithm provides a smooth, musical reverb tail that works well on everything from vocals to synthesizers. This reverb only functions in mono and provides no stereo imaging, and the user can expect the same behavior as a classic Freeverb implementation otherwise.
Screenshots
Verdict
MIDI and Callback Freeverb are too close to call on the numbers: across 8 compared parameters — price, rating, ratings volume and ads among them — neither pulls far enough ahead to decide it. What separates them is feature set and interface, not measurable difference.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
On the App Store both sit at effectively the same score — 5.0 for MIDI against 5.0 for Callback Freeverb. Both are backed by a comparable volume of ratings — 1 and 1 respectively.
| Parameter | MIDI | Callback Freeverb |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (1 ratings) | 5.0 (1 ratings) |
| Number of ratings | 1 | 1 |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPad | iPhone, iPad |
| Requires iOS | 18.6 | 17.0 — better |
| Further details — not scored | ||
| Size | 5 MB | 7 MB |
| Age rating | 4+ | 4+ |
| Developer | Michael Hitz | Callback Audio, LLC |
In-app purchases
MIDI
No in-app purchases
Callback Freeverb
No in-app purchases









