JP vs 4trMTR
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
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.
- 8 Analog Synth Voices
- Authentic VCF Control
- ADSR Envelope
- Arpeggiator with 5 Patterns
- Split and Solo Modes
- Reverb & Chorus Effects
- Pitch Lever
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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.
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.
- Four-track recording
- Layered performances
- Project saving
- Project loading
- New project creation
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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
Verdict
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
JP is free to download; 4trMTR costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.
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.
| Parameter | JP | 4trMTR |
|---|---|---|
| Price | Free — better | $1.99 |
| Rating | 1.0 (1 ratings) — better | — |
| Positive reviews | 0.0% of reviews | 100.0% of reviews — better |
| Number of ratings | 1 — better | — |
| Update frequency | Every 2 weeks — better | Every 3 weeks |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPad | iPhone, iPad |
| Requires iOS | 26.5 | 17.6 — better |
| Further details — not scored | ||
| Size | 37 MB | 12 MB |
| Age rating | 4+ | 4+ |
| Developer | Kouki Yoshimoto | YUKIO TOKIWA |
Customer experience
JP
4trMTR
In-app purchases
JP
No in-app purchases
4trMTR
No in-app purchases









