C.ARP vs Omni
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
C.ARP
This app offers a unique approach to music creation, inspired by vintage instruments. It allows users to play chords and melodies with intuitive touch controls, apply real-time audio effects, and utilize a dynamic rhythm section. Advanced features include sampling, MIDI output via Bluetooth, and an iPad-optimized interface.
- Chord and melody playing
- Real-time audio effects
- Dynamic rhythm section
- Sampling and looping
- MIDI output via Bluetooth
- iPad optimized interface
- In-app tutorial
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C.ARP is a totally different keyboard. Inspired by old keyboards, omnichords and tape effects, it lets you play chords and melodies as well. Its design makes everything easier for a musician who just wants to play on mobile. Just hold on a button and then swipe or tap on the right section. But if you prefer, you can access chords and notes directly on the notes grid. Pitch them, harmonize, use mod wheel and apply real-time audio effects too. Rhythm section follows you every chord you choose: pick up the style you prefer, adjust BPMs, mute other instrument, change different midi settings, change drums and play them with drum pads. Do arpeggios with different sounds and rhythmic fractions, create different sound environments with delay, reverb and rotation. The design has also been updated for iPads, so you can enjoy the buttons and sections rearranged for the screen size. Record your voice or everything else as a sample, adjust its length, reverse or loop it, make chords and melodies with it and explore other cool features on this 4th version. There's also a tutorial inside! And finally: we added bluetooth out. It means you can connect your iPhone to your Mac and send midi notes right in your preferred DAW. Just follow the guide inside. Thanks to everyone who helped me: Giacomo, Virginia, Mattia, Andrea, Giulia, Cristiano, and the others. Thanks to the masters Suriani, Frankie and Calcutta. For every question or suggestion don't hesitate to write to me
Omni
Create music with a touch-first instrument for chords, strums, and rhythmic ideas. Shape synth sounds, add effects, and send MIDI to other apps or hardware. Designed for fast, expressive musical performance without complexity.
- Touch-based chord and strum performance
- Dual synth engines with performance controls
- Built-in ARP and drum sequencer
- Performance effects (reverb, delay, etc.)
- Customizable chord layouts
- MIDI Out for external control
- AUv3 Instrument support
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Omni: Pocket Synth is a compact, touch-first instrument for creating chords, strums, arpeggios, pads, keys, and rhythmic musical ideas with an immediate performance workflow. Play harmonic layouts directly from the screen, shape two independent pocket synth engines, add motion and effects, and send MIDI to other apps or hardware. Omni is designed to feel fast, musical, and expressive without turning into a complex workstation. Features: - Touch-based chord and strum performance. - Chord Voice and Strum Voice with independent sound controls. - Wavetable and subtractive / virtual analog voice engines with focused pocket controls. - Hold / latch modes for Chord and Strum performance. - Multiple strum modes including Standard, Extended, Pentatonic, Scale, and Chromatic Touchplates. - Built-in ARP with musical patterns, rate, octaves, gate, and swing. - Simple drum engine with kick and snare sequencing. - Reverb, delay, vibrato, and autopan performance effects. - Layout Editor for custom chord layouts. - MIDI In for playing from external controllers. - MIDI Out for controlling other apps, AUv3 instruments, or hardware synths. - Hold / latch performance can also be used with MIDI Out. - AUv3 Instrument support for hosts such as AUM. - Independent Chord MIDI Out and Strum MIDI Out in AUv3 hosts. - Preset Manager with factory and user presets. Omni works both as a standalone app and as an AUv3 instrument. In AUv3 hosts, you can route Chord and Strum MIDI outputs separately, making it easy to control different instruments from one performance surface. The free version includes the core playing experience. Omni Pro unlocks the full preset workflow, AUv3 support, advanced strum modes, Layout Editor, MIDI Out, and other creative tools.
Screenshots
Verdict
The clearest difference is price: Omni at Free against C.ARP's $9.99. Omni also leads on rating (5.0 vs 4.3). C.ARP's advantage is in-app purchases (none vs 1) and ratings volume (114 vs 4). On update cadence, ads and device support 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
Omni is free to download; C.ARP costs $9.99 up front. Omni sells 1 one-off in-app purchase. C.ARP asks for nothing beyond the download.
Omni holds the better App Store score, 5.0 against 4.3. That said, the two scores are not equally well evidenced: C.ARP has 114 ratings behind it against 4, so its average is the more settled of the two.
C.ARP ships an update every 4 weeks, Omni fortnightly. Both last shipped on September 22, 2026.
| Parameter | C.ARP | Omni |
|---|---|---|
| Price | $9.99 | Free — better |
| Rating | 4.3 (114 ratings) | 5.0 (4 ratings) — better |
| Positive reviews | 74.3% of reviews | — |
| Number of ratings | 114 — better | 4 |
| Update frequency | Every 4 weeks | Fortnightly — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Freemium |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 13.0 — better | 18.0 |
| Further details — not scored | ||
| Size | 45 MB | 12 MB |
| Age rating | 4+ | 4+ |
| Developer | Paolo Giorgi | Ruben Terron Rodriguez |
Customer experience
C.ARP
Omni
Bugs and requests
C.ARP
Reported bugs
40 issues- Sound doesn't work
- No sound
- App crashes when opening
- App crashes when trying to open
- App auto-quits on start
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- Chord panel smaller after update
- System setting always out
- App crashes after using only once
- App crashes when pressing a button
- MIDI Send is broken
- Can't open the app on Mac
- Can't close the menu
- App crashes if sample button is pressed
- Sample button crashes the app
- Strumming doesn't work
- App crashes when sample or reverse is pressed
- App is not stable / crashy
- Sampling function is DOA
- Sampler doesn't work / crashes
- Crash problem
- Send midi function greyed out
- App crashes when pressing the red sample button
- Sampler crashes the app 100%
- App crashes when attempting to use record feature
- Sample button keeps crashing the app
- Record, loop, or reverse buttons cause crash
- Bugs related to recording/sampling
- Sampler may crash
- Audio panel covers gear button
- E chord is extremely low octave and sounds muddled
- App crashes when trying to start an audio recording
- Certain audio glitches with recording and looping
- Buttons crash the app
- App crashes when pressing the sample button
- Sample and reverse buttons crash the app
- MIDI out doesn't seem to work
- Latency is a killer
- Chord doesn't trigger if not hit perfectly
- Sliding finger doesn't sound chord
- Sound can be tinny/harsh
Requested features
18 requests- Rearrange layout to be chromatic
- AUV3 support
- Inter-app-audio / GarageBand integration
- MIDI out functionality
- Save last state
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- Contextual help menus
- More sound design options
- Make it an Auv3 midi controller
- Support iPad
- Add "midi out" option
- Make it an audio app extension for GarageBand
- Add a way to use this app as a Bluetooth midi controller
- Add a visual distinction for individual buttons
- Add velocity on the strum bar
- Allow autoplay chord to hold like a drone
- Transpose reverb of strummed notes
- Add midi connectivity with external devices and other apps
- Add custom colors for themes
Omni
Not enough reviews yet to summarise bugs or requests.
In-app purchases
C.ARP
No in-app purchases
Omni
- Omni Pro$8.99





