Comparison

MIDI Controller/Oscilloscope vs Callback Freeverb

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

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.

Highlights
  • 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
Features
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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.

About

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.

Highlights
  • Classic Freeverb algorithm
  • Schroeder/Moorer reverb topology
  • Comb and allpass filters
  • Mono operation
  • Adds depth and space to audio
  • Smooth, musical reverb tail
Features
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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

MIDI Controller/Oscilloscope3 screens
Callback Freeverb4 screens

Verdict

The call

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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

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.

ScorecardNo meaningful differences
MIDI Controller/Oscilloscope versus Callback Freeverb: the parameters behind the verdict, then further details
ParameterMIDI Controller/OscilloscopeCallback Freeverb
PriceFreeFree
Rating5.0 (1 ratings)5.0 (1 ratings)
Number of ratings11
AdsNoNo
In-app purchasesNoNo
MonetizationFreeFree
DevicesiPhone, iPadiPhone, iPad
Requires iOS17.017.0
Further details — not scored
Size1 MB7 MB
Age rating4+4+
DeveloperCollective Vision, LLC.Callback Audio, LLC

Customer experience

MIDI Controller/Oscilloscope

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

Callback Freeverb

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

MIDI Controller/Oscilloscope

No in-app purchases

None

Callback Freeverb

No in-app purchases

Questions

Is MIDI Controller/Oscilloscope free?
MIDI Controller/Oscilloscope is free to download, with no in-app purchases.
Is Callback Freeverb free?
Callback Freeverb is free to download, with no in-app purchases.
Which has better reviews, MIDI Controller/Oscilloscope or Callback Freeverb?
MIDI Controller/Oscilloscope and Callback Freeverb are both rated 5.0 out of 5 on the App Store, from 1 and 1 ratings respectively.
Do MIDI Controller/Oscilloscope or Callback Freeverb have ads?
Neither MIDI Controller/Oscilloscope nor Callback Freeverb shows ads.

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