Comparison

JP vs 4trMTR

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

Head to head
About

JP

This application emulates a legendary analog polyphonic synthesizer, offering 8 distinct analog synth voices. Users can sculpt sounds with authentic VCF and ADSR controls, utilize an arpeggiator, and split the keyboard for dual-sound performance. Built-in effects and pitch lever allow for expressive sound design on the go.

Highlights
  • 8 Analog Synth Voices
  • Authentic VCF Control
  • ADSR Envelope
  • Arpeggiator with 5 Patterns
  • Split and Solo Modes
  • Reverb & Chorus Effects
  • Pitch Lever
Features
Read full description

An iPhone app that recreates the legendary analog polyphonic synthesizer. [Key Features] 8 Analog Synth Voices: JP-Brass / JP-Strings / JP-Warm Pad / JP-Choir / JP-Saw Lead / JP-Square / JP-Bass / JP-Bell Authentic VCF Control: Manipulate Cutoff, Resonance, and ENV in real time. Shape your sound freely by sweeping the filter. ADSR Envelope: Intuitively control Attack, Decay, Sustain, and Release via sliders. Arpeggiator: 5 patterns (Up, Down, U&D, As Play, Random) with adjustable BPM and octave range. Split Mode: Split the keyboard into two zones to play two different sounds simultaneously. Solo Mode: Monophonic operation tailored for searing lead lines and solo play. Reverb & Chorus: Add depth and space to your sound with built-in spatial effects. Pitch Lever: Perform expressively with real-time pitch bends. LFO / VCO Control: Create rich, evolving textures with modulation. [Recommended For] Fans of iconic '80s synth sounds. Music producers and DTM creators. Anyone looking to enjoy synthesis on the go. Those who love the signature "JP voice" sound. *This app contains ads. *Using headphones or external speakers is highly recommended for the best sound experience.

About

4trMTR

Record and layer multiple musical performances one track at a time to create a complete song. Easily manage your projects by saving, loading, and creating new ones through a simple tap interface.

Highlights
  • Four-track recording
  • Layered performances
  • Project saving
  • Project loading
  • New project creation
Features
Read full description

iPhoneを、シンプルな4トラックMTRに。 4trMTRは、ギター、ベース、ボーカルなどを1トラックずつ重ねて録音できる、シンプルなマルチトラックレコーダーです。 曲のアイデアを思いついたとき。 バンドのデモを作りたいとき。 楽器や歌を重ねて録音したいとき。 複雑なDAWを立ち上げなくても、iPhoneですぐに録音を始められます。 【シンプルな4トラック録音】 4つのトラックを使って、演奏や歌を重ねて録音できます。 例えば、 Track 1:ギター Track 2:ボーカル Track 3:ベース Track 4:コーラス といった使い方ができます。 【パンチイン録音】 録り直したい部分だけを指定して再録音できます。 演奏の一部分を修正したいときにも、最初からすべて録り直す必要はありません。 【入力を選んで録音】 利用可能な入力から、録音に使用する入力を選択できます。 iPhoneだけで手軽に録音したり、対応する外部オーディオ機器を使った録音にも活用できます。 【プロジェクトとして保存】 録音した内容はプロジェクトとして管理できます。 曲のアイデアやデモを残し、あとから続きを録音できます。 【シンプルだから、すぐ録れる】 初めてのレコーディングはカセットでした。 大した機能はなかったけれど、何でも作れる気がしました。 4trMTRは、そんなシンプルな録音の楽しさをiPhoneで再現するためのアプリです。 たくさんの機能を覚えるより、まず録音する。 楽器を持って、RECを押して、音を重ねる。 4trMTRで、あなたの曲のアイデアを残してみてください。

Screenshots

JP4 screens
4trMTR3 screens

Verdict

The call

The clearest difference is review sentiment: 4trMTR at 100% against JP's 0%. 4trMTR also leads on iOS requirement (17.6 vs 26.5). JP's advantage is price (Free vs $1.99). On update cadence, 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

JP is free to download; 4trMTR costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

JP ships an update every 2 weeks, 4trMTR every 3 weeks. The most recent releases landed on November 7, 2026 and November 5, 2026 respectively.

Scorecard3 real differences · 7 level
JP versus 4trMTR: the parameters behind the verdict, then further details
ParameterJP4trMTR
PriceFree — better$1.99
Rating1.0 (1 ratings) — better—
Positive reviews0.0% of reviews100.0% of reviews — better
Number of ratings1 — better—
Update frequencyEvery 2 weeks — betterEvery 3 weeks
AdsNoNo
In-app purchasesNoNo
MonetizationFreeFree
DevicesiPhone, iPadiPhone, iPad
Requires iOS26.517.6 — better
Further details — not scored
Size37 MB12 MB
Age rating4+4+
DeveloperKouki YoshimotoYUKIO TOKIWA

Customer experience

JP

All ratings1 ratings
Positive0.0%
Neutral0.0%
Negative100.0%
Written reviews1 reviews
Positive0.0%
Neutral0.0%
Negative100.0%

4trMTR

Written reviews2 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

JP

No in-app purchases

None

4trMTR

No in-app purchases

Questions

Is JP free?
JP is free to download, with no in-app purchases.
Is 4trMTR free?
4trMTR costs $1.99, with no in-app purchases.
Do JP or 4trMTR have ads?
Neither JP nor 4trMTR shows ads.
Which is updated more often, JP or 4trMTR?
JP ships an update every 2 weeks, and 4trMTR every 3 weeks. Most recently, JP was updated on November 7, 2026 and 4trMTR on November 5, 2026.

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