Xkey Plus vs FabFilter Twin 3
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Xkey Plus
This app enhances the functionality of ESI Xkey musical keyboards on mobile devices. It allows users to update firmware, customize velocity curves, and configure key sensitivity and timings for an advanced user experience.
- Check for new Xkey firmware
- Velocity curves editor
- Configure Xkey sensitivity & timings
- Access all Xkey parameters
- Configure key & button assignments
- Access Xkey documentation & support
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◆◆◆ Xkey Plus ◆◆◆ This app is dedicated to ESI Xkey musical keyboard. It is an ideal companion to your mobile keyboard. FEATURES ◆ Check for new Xkey firmware ◆ Velocity curves editor ◆ In-depth configuration of Xkey sensitivity & timings (advanced users) ◆ Access to all Xkey parameters (advanced users) ◆ Possibility to configure new assignments to all keys & buttons (requires Fw 1.2+) ◆ Direct access to Xkey documentation & support REQUIREMENTS ◆ Xkey musical keyboard ◆ USB cam kit or lightning cable ◆ Compatible with iPad (iOS 7 or later) Do not hesitate to contact us if you find any problem on this app. If you like this app, don't forget to write a positive review ! ESI
FabFilter Twin 3
This powerful virtual analog synthesizer offers a vast array of sound-shaping tools, including multiple oscillators, filters, and a comprehensive modulation system. Create a wide range of synth sounds with an intuitive interface and a rich factory preset library.
- Four flexible oscillators
- Four vintage-style filters
- Extensive modulation system
- All-new FX section
- Arpeggiator with groove controls
- Full-featured preset browser
- Analog-modelled drift
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Since its first release in 2005, FabFilter Twin has been famous for its filter quality and oscillator sound. FabFilter Twin 3 expands and improves on its predecessors in every area, including a complete redesign of the GUI and workflow, more and better oscillators and filters, a radically powered-up modulation system, an all-new FX section, and much more. Sonically versatile, supremely intuitive, and spectacularly ‘analog’, Twin 3 is a dream instrument for creating synth sounds of all kinds, from basses, leads, and pads to plucks, drums, effects, and beyond. The Twin 3 app lets you play via the on-screen keyboard or a MIDI keyboard connected to your iPad. To use Twin 3 as a plug-in, you need an AUv3-compatible host app like Auria, AUM or Cubasis. Twin 3 will appear in the list of Audio Unit extensions for instrument plug-ins in the host app. Key features: - Virtual analog synth featuring four flexible oscillators, four filters, six FX modules, and a vast modulation system with a wealth of flexible source signal generators, drag and drop source/target routing, and no limit to the number of modulation assignments that can be made - Fully redesigned, greatly simplified interface with easier workflow - Completely overhauled modulation system with redesigned modulation sources, and floating slot and FX panels - All-new FX section, housing Reverb, Delay, Chorus, Phaser, Drive, and Compressor modules - Arpeggiator with Groove/Legato controls, note order, latch options, and more - Full-featured preset browser, with tags, favorites, and search and filter functions, and new factory preset library - Per Oscillator polyphony mode: each incoming note triggers a different oscillator - Bell, Shelf, and Notch vintage-style EQ filter shapes - 6dB/octave filter slope option - Modulatable filter Cutoff/Peak Offset knobs knobs, for adjusting all filters at once - High Quality mode — 4x oversampling - Transient mode turns Envelope Followers into transient detectors - Curve adjustment handles for EG Attack, Decay, and Release stages - Slider mode (vertical-only operation) and Range setting (toggles between bipolar and unipolar behavior) for XY controllers - Hide all modulation sources except for XY controllers and Sliders at a click - Native sustain pedal support - Even better oscillator and filter sound quality, with analog-modelled drift - Maximum number of voices doubled from 32 to 64 - Lower minimum Envelope Generator Attack, Decay, and Release times - Maximum number of XY controllers/Sliders increased to six - Envelope Generator Threshold, XLFO Balance, and Frequency Offset made available as modulation targets - Modulation sources can be renamed - Maximum number of modulation slots increased to 100 - Legato mode for MIDI-triggered XLFO - Range options added to MIDI Sources: Negative (-1 to 0), Centered (-1 to 1), and Positive (0 to 1) - Carefully designed and curated factory presets, plus the ability to save your own presets - Undo/redo and A/B comparison "FabFilter Twin is one of the best virtual analogues we've heard so far, and at this price point it's well worth the investment!" — Computer Music "Once I found FabFilter Twin, I immediately noticed how great it works and how amazing it sounds!" — George Morel
Verdict
The clearest difference is review sentiment: FabFilter Twin 3 at 86% against Xkey Plus's 36%. FabFilter Twin 3 also leads on rating (4.6 vs 2.9) and ratings volume (42 vs 13). Xkey Plus's advantage is price (Free vs $24.99) and update cadence (every 3 months vs every 19 months). On ads, in-app purchases 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
Xkey Plus is free to download; FabFilter Twin 3 costs $24.99 up front. Neither carries in-app purchases, so what you see is what you pay.
FabFilter Twin 3 holds the better App Store score, 4.6 against 2.9. Both are backed by a comparable volume of ratings — 13 and 42 respectively. Written reviews point the same way: 36% of Xkey Plus's written reviews are positive against 86% of FabFilter Twin 3's.
Xkey Plus ships an update every 3 months, FabFilter Twin 3 every 19 months. The most recent releases landed on June 6, 2026 and September 20, 2026 respectively.
| Parameter | Xkey Plus | FabFilter Twin 3 |
|---|---|---|
| Price | Free — better | $24.99 |
| Rating | 2.9 (13 ratings) | 4.6 (42 ratings) — better |
| Positive reviews | 35.7% of reviews | 86.2% of reviews — better |
| Number of ratings | 13 | 42 — better |
| Update frequency | Every 3 months — better | Every 19 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free — better | Paid |
| Devices | iPad | iPad |
| Requires iOS | 9.3 — better | 14.0 |
| Further details — not scored | ||
| Size | 9 MB | 11 MB |
| Age rating | 4+ | 4+ |
| Developer | ESI Audiotechnik GmbH | FabFilter |
Customer experience
Xkey Plus
FabFilter Twin 3
In-app purchases
Xkey Plus
No in-app purchases
FabFilter Twin 3
No in-app purchases









