OFFBEAT — Rhythm Trainer

OFFBEAT is a rhythm training app built for ska punk and jazz musicians.

■ Train the "gap" a metronome can't teach you Just tapping along with a metronome doesn't build the feel you need on stage. OFFBEAT focuses on the genre-specific placement of rhythm — offbeats only, the third note of the swing triplet, the 2 & 4 backbeat — and visualizes your timing error in milliseconds.

■ 6 specialized training modes

• Offbeat Master (free) — the 8th-note offbeat that underpins ska cutting
• Swing Pocket (free) — the "third triplet" feel of jazz time
• 2 & 4 Backbeat — the shared backbone of jazz and ska
• Silent Keep — hold your internal groove through bars of silence
• Tempo Sprint — survive accelerating tempos without rushing
• Call & Response — hear a phrase, play it back

■ Output latency calibration Measures the output delay of your earphones/speaker and folds it into the judgment, resolving the feeling of being "off" when you're actually on time. That said, since Bluetooth latency itself fluctuates, please use wired earphones or a speaker.

■ Built to keep you coming back

• Three 30-day lesson courses (All-round / Ska focus / Jazz focus)
• Day-streak tracking with a weekly one-day protection freeze
• Timing diagnosis after every session: are you rushing or dragging?
• Score, accuracy and average offset recorded every run

[Pricing]

• The app is free to download.
• "Offbeat Master" and "Swing Pocket" are free forever, with no time limit.
• A single purchase unlocks the other four modes (2&4 Backbeat, Silent Keep, Tempo Sprint, Call & Response) and all three 30-day lesson courses (All-round, Ska, Jazz).
• This is a one-time purchase, not a subscription. Once you buy it, the content listed above is yours to keep.
• After reinstalling or switching devices, use "Restore Purchase" in Settings.

■ Privacy All play data stays on your device. Nothing is transmitted (see the privacy policy for details).

For you if:

• You play in (or want to join) a ska punk or jazz band
• You can follow a metronome but can't sit in the groove
• You've ever been told you rush on the offbeats

— From the developer

I've played in a ska punk band and spent years touring the jazz cafés of Japan, yet I never trusted my own sense of rhythm. Metronomes and method books didn't fix it. "It isn't talent — there has to be a way to train this." So I built it with the one skill I did have: programming. That's how OFFBEAT began. Not for people who already have rhythm, but for those who struggle, like I did. Starting with ska and jazz — and someday, for every player, in every genre.