Comparison

Xkey Plus vs Guitar Permutation Trainer

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

Head to head
About

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.

Highlights
  • Check for new Xkey firmware
  • Velocity curves editor
  • Configure Xkey sensitivity & timings
  • Access all Xkey parameters
  • Configure key & button assignments
  • Access Xkey documentation & support
Features
Read full description

◆◆◆ 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

About

Guitar Permutation Trainer

Features
Read full description

Guitar Permutation Trainer helps you practice finger permutations across your fretboard with a built‑in metronome and adaptive difficulty. Practicing permutation exercises on instruments like guitar, bass, and piano targets the small, intrinsic muscles of the hand and fingers, such as the lumbricals and interossei. These muscles are responsible for fine motor control, finger independence, and strength. Repetitive, structured movement patterns improve neuromuscular coordination by reinforcing neural pathways between the brain and fingers - a process known as motor learning. According to research in kinesiology and occupational therapy, consistent practice builds endurance and prevents overuse injuries by promoting balanced muscle development. For developing musicians, this foundation is essential for achieving speed, accuracy, and long-term technical reliability without strain.

Screenshots

Guitar Permutation Trainer4 screens

Verdict

The call

The clearest difference is price: Xkey Plus at Free against Guitar Permutation Trainer's $1.99. Xkey Plus also leads on iOS requirement (9.3 vs 18.4). Guitar Permutation Trainer's advantage is update cadence (every 3 days vs every 3 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

CostPrice · In-app purchases · Ads · Monetization

Xkey Plus is free to download; Guitar Permutation Trainer costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

Xkey Plus ships an update every 3 months, Guitar Permutation Trainer every 3 days. The most recent releases landed on September 24, 2026 and October 10, 2026 respectively.

Scorecard3 real differences · 7 level
Xkey Plus versus Guitar Permutation Trainer: the parameters behind the verdict, then further details
ParameterXkey PlusGuitar Permutation Trainer
PriceFree — better$1.99
Rating2.9 (13 ratings) — better—
Positive reviews35.7% of reviews—
Number of ratings13 — better—
Update frequencyEvery 3 monthsEvery 3 days — better
AdsNoNo
In-app purchasesNoNo
MonetizationFree—
DevicesiPadiPhone, iPad — better
Requires iOS9.3 — better18.4
Further details — not scored
Size9 MB3 MB
Age rating4+4+
DeveloperESI Audiotechnik GmbHBenjamin Chouinard

In-app purchases

None

Xkey Plus

No in-app purchases

None

Guitar Permutation Trainer

No in-app purchases

Questions

Is Xkey Plus free?
Xkey Plus is free to download, with no in-app purchases.
Is Guitar Permutation Trainer free?
Guitar Permutation Trainer costs $1.99, with no in-app purchases.
Do Xkey Plus or Guitar Permutation Trainer have ads?
Neither Xkey Plus nor Guitar Permutation Trainer shows ads.
Which is updated more often, Xkey Plus or Guitar Permutation Trainer?
Xkey Plus ships an update every 3 months, and Guitar Permutation Trainer every 3 days. Most recently, Xkey Plus was updated on September 24, 2026 and Guitar Permutation Trainer on October 10, 2026.

Other comparisons