Guide

So you want that strumplate sound on your iPhone

You've heard it on a record, or seen someone sweep their thumb across a rainbow of strings in a video, and now you want one. Here's the honest situation in 2026 — what the original instruments did, why they cost what they cost, and what your actual options are.

What the instrument actually was

In the early 1980s, Japanese manufacturers took the old parlour autoharp — a boxed zither with chord bars — and made it electronic. You pressed a chord button with one hand and swept a flat, touch-sensitive plate with the other. The plate had no strings on it at all; it triggered notes from a synthesiser, and crucially it only ever triggered notes belonging to the chord you were holding.

That one design decision is why these machines mattered. You could not play a wrong note. Someone who had never touched an instrument could produce a shimmering, perfectly-tuned chord within four seconds of picking it up. For songwriters, that removed the gap between having an idea and hearing it — which is the gap most ideas die in.

The sound is unmistakable: bright, glassy, slightly synthetic, with a long chiming tail. It turned up on a lot of records through the '80s, '90s and again in the 2000s when a new generation found them in second-hand shops.

Why buying the hardware is hard now

None of that means don't buy one. If you love objects, an original is a joy and holds its value. But if what you want is the playing experience, a phone is a surprisingly good answer — because the thing being reproduced was always an interface idea plus a synthesiser, and a modern phone does both.

What to look for in an app

There are a handful of apps in this space and they vary enormously. These are the things that actually determine whether you'll still be playing it in a month:

CheckWhy it matters
Synthesis, not samplesSamples loop and flatten. A real engine responds to how hard and fast you sweep, which is most of the expressiveness.
Velocity from finger speedWithout it, every strum sounds identical and the instrument dies after ten minutes.
Haptics per stringGlass gives you no feedback. A tick per string is what makes it feel like an instrument rather than a screen.
Enough chordsMajors, minors and sevenths is the floor. Sus4, add9, diminished and augmented are what let you play actual songs.
Background audioSo you can jam over a track playing in another app.
MIDI outTurns it from a toy into a chord controller for GarageBand, Logic, AUM or hardware.
One priceSubscriptions and "pro voice packs" on a £5 instrument are a bad sign about everything else.

Where PocketStrum fits

PocketStrum is our answer to exactly this brief, and yes — we made it, so read this with that in mind. It's an independent tribute to the class of instrument described above, written from scratch. It isn't a reissue, an emulation of any particular product, or affiliated with or endorsed by any hardware manufacturer.

What's in it:

£4.99, once. No subscription, no in-app purchases, no ads, no account, and the App Store privacy label reads Data Not Collected.

Try it before you spend anything

There's a working strumplate on the front page of this site. Six chords, four voices, no download and no email address. If sweeping it doesn't make you smile, don't buy the app.

Go and play it

A few honest caveats

If it's for a child

Under about seven, the full chord panel is more than they need and the pleasure gets lost in the complexity. Wonderchord is the same idea rebuilt for ages 2–6 — six colour pads instead of thirty-six keys, rainbow strings, nine familiar songs, and a lesson mode that waits as long as they need.


Published 7 August 2026 · Written by Connor Clements