Comparison

Callback Freeverb vs Hoverophone

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

Head to head
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
Read 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.

About

Hoverophone

This app reimagines the theremin for your iPhone, allowing you to play music by waving your hands in the air without touching the screen. It offers a polyphonic synthesizer with various sound options and microtonal capabilities for unique musical exploration.

Highlights
  • Air-based theremin playing with front camera hand tracking
  • Polyphonic synthesizer with multiple voice options
  • Microtonal keyboard with 12-TET or 24-TET quarter tones
  • Stack up to twelve notes by pinning voices
  • Continuous pitch glide and volume control
  • Fully offline functionality
Features
Read full description

The theremin, reinvented on your iPhone. Play it in the air with your hands, no touch. Hoverophone is a theremin you actually play by waving your hands in the air. Point the front camera at your hand and move; there is no touch, no controller, no tapping glass. Raise and lower your hand to glide the pitch, spread your thumb and finger apart to swell the volume, slide left to right to pan. It is the eerie, sci-fi theremin sound, played with a wave of the hand. Wondering how to play the theremin, or whether the theremin is hard to play? This is the easiest way to start: raise a hand and you are already playing. A REAL SYNTH, AND POLYPHONIC Continuous synth voices, sine, triangle, saw and square, with drive and ring modulation in stereo, from a soft ambient pad to a metallic, otherworldly drone. It tracks up to four hands at once, so a theremin can finally play chords, and you can pin voices in place to hold up to twelve notes ringing together. Tune the sound with one hand while you play with the other. MICROTONAL, PLAYED IN THE AIR Turn on the note grid and your in-air pitch snaps to a scale: 12-TET, or 24-TET quarter tones for real microtonal play. It is an isomorphic, honeycomb hex keyboard you play in the air, not by tapping glass, so every note lands in tune while your hands stay above the camera. Explore microtonal music, quarter tones and xenharmonic scales the moment you raise a hand, or leave the grid off and glide freely for the pure continuous theremin. WHAT YOU CAN DO - Play a real theremin in the air, front-camera hand tracking, no touch - The classic continuous theremin glide, the sci-fi movie sound - An in-air microtonal keyboard: 12-TET or 24-TET quarter tones on an isomorphic hex grid, or fully continuous - Polyphonic: up to four hands live, and pin voices to stack up to twelve - Synth voices with drive and ring modulation, stereo panning as you move - Plays through the speaker or headphones, even on silent - Fully offline: no account, no network, no data collected, the camera is processed on device and never leaves it No presets, no wall of knobs, just your hand and the air. Fill a room with an ambient drone, improvise a generative soundscape, or conjure the spooky whine of a sci-fi movie. Works best in a bright room where the camera can see your hands.

Screenshots

Callback Freeverb4 screens
Hoverophone4 screens

Verdict

The call

The clearest difference is rating: Callback Freeverb at 5.0 against Hoverophone's 4.3. Hoverophone's advantage is ratings volume (3 vs 1). On price, ads, in-app purchases and monetization model 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

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

Callback Freeverb holds the better App Store score, 5.0 against 4.3. Both are backed by a comparable volume of ratings — 1 and 3 respectively.

Scorecard2 real differences · 8 level
Callback Freeverb versus Hoverophone: the parameters behind the verdict, then further details
ParameterCallback FreeverbHoverophone
PriceFreeFree
Rating5.0 (1 ratings) — better4.3 (3 ratings)
Positive reviews—50.0% of reviews
Number of ratings13 — better
Update frequency—Weekly
AdsNoNo
In-app purchasesNoNo
MonetizationFreeFree
DevicesiPhone, iPadiPhone, iPad
Requires iOS17.0 — better17.6
Further details — not scored
Size7 MB4 MB
Age rating4+4+
DeveloperCallback Audio, LLCMaxim Oransky

Customer experience

Callback Freeverb

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

Hoverophone

All ratings3 ratings
Positive66.7%
Neutral33.3%
Negative0.0%
Written reviews2 reviews
Positive50.0%
Neutral50.0%
Negative0.0%

In-app purchases

None

Callback Freeverb

No in-app purchases

None

Hoverophone

No in-app purchases

Questions

Is Callback Freeverb free?
Callback Freeverb is free to download, with no in-app purchases.
Is Hoverophone free?
Hoverophone is free to download, with no in-app purchases.
Which has better reviews, Callback Freeverb or Hoverophone?
Callback Freeverb is rated higher. Callback Freeverb averages 5.0 out of 5 from 1 ratings, while Hoverophone averages 4.3 from 3 ratings.
Do Callback Freeverb or Hoverophone have ads?
Neither Callback Freeverb nor Hoverophone shows ads.

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