MIDI Controller/Oscilloscope vs Callback Freeverb
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
MIDI Controller/Oscilloscope
This app combines a multi-touch performance keyboard, a 16-channel step sequencer, and a real-time oscilloscope. It allows seamless integration with hardware synthesizers and audio gear via USB, enabling music creation and analysis.
- Multi-touch velocity-sensitive keyboard
- 16-channel step sequencer with piano roll
- Real-time 8-channel oscilloscope
- USB MIDI and audio interface support
- Network and Bluetooth MIDI compatibility
- Live recording and transposition
- Sub-millisecond sequencer timing
Read full descriptionHide full description
A powerful all-in-one studio companion for hardware synthesizers, drum machines, and audio gear. Connect your USB MIDI devices and audio interfaces and start playing, sequencing, and analyzing instantly. KEYS — Multi-Touch Performance Keyboard • 3-octave velocity-sensitive piano with multi-finger support • Velocity from touch position — soft on top, loud at the bottom • Spring-loaded pitch bend wheel (14-bit precision) • Mod wheel (CC#1) for expressive control • Program change selector with quick recall • Octave shifting from -2 to +5 • Per-channel routing to different synths • Transpose mode — keyboard transposes the live sequence SEQ — 16-Channel Step Sequencer • 16 independent MIDI channels, up to 32 steps each • Mono mode for melody and bass lines • Poly mode with full piano roll editor • Swing control for groove (0-50%) • Live recording from your external keyboard • MIDI clock sync — auto-detects tempo from incoming clock • Per-channel destination routing — each track plays a different synth • Live transpose during playback • Adjustable note range and pattern length SCOPE — Real-Time Multi-Channel Oscilloscope • Up to 8 channels simultaneously from USB audio interfaces • 1-2-5 standard time/division (10 microseconds to 500 ms) • Configurable voltage/division with auto-scale • Rising and falling edge trigger with adjustable level • Auto and Normal trigger modes • Per-channel color, vertical offset, and on/off • Phosphor persistence with adjustable decay • Glow effect with intensity control • Three background themes — Classic, Space, Shockwave • Metal-accelerated rendering CONNECTIVITY • USB MIDI — plug in your hardware controllers and synths • USB audio interfaces — multi-channel input for the oscilloscope • Network MIDI / Bluetooth MIDI compatible • Companion iPhone app — record video while iPad captures audio over Wi-Fi (Bonjour) DESIGNED FOR PERFORMANCE • Sub-millisecond sequencer timing • Lock-free audio buffers for glitch-free capture • Optimized for iPad landscape — full immersive UI • Per-app settings for every channel, every parameter, persistent across sessions Whether you're sketching ideas in the studio, performing live, debugging a Eurorack patch, or learning synthesis, this app brings keyboard, sequencer, and oscilloscope into a single, fast, focused interface. No ads. No subscriptions. No accounts. Just plug in and play.
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
Read full descriptionHide full description
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 Controller/Oscilloscope 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 Controller/Oscilloscope against 5.0 for Callback Freeverb. Both are backed by a comparable volume of ratings — 1 and 1 respectively.
| Parameter | MIDI Controller/Oscilloscope | 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 | 17.0 | 17.0 |
| Further details — not scored | ||
| Size | 1 MB | 7 MB |
| Age rating | 4+ | 4+ |
| Developer | Collective Vision, LLC. | Callback Audio, LLC |
Customer experience
MIDI Controller/Oscilloscope
Callback Freeverb
In-app purchases
MIDI Controller/Oscilloscope
No in-app purchases
Callback Freeverb
No in-app purchases
Questions
Is MIDI Controller/Oscilloscope free?
Is Callback Freeverb free?
Which has better reviews, MIDI Controller/Oscilloscope or Callback Freeverb?
Do MIDI Controller/Oscilloscope or Callback Freeverb have ads?
Other comparisons















