IPHONE DUOComing with iPhone Duo

Fold it. It's a music stand.

Half fold the iPhone Duo like a laptop and Chartless splits the screen at the fold. What you read stands up on the top half. What you touch lies flat on the bottom half. Nothing is drawn under the crease.

Three screens know about the fold: Stage, the song chart, and the tuner. This isn't in the App Store build yet. It ships once Apple's tools for the Duo are final.

Stage mode on a half-folded iPhone Duo: a large G with next D standing on the top half; the chord diagram, brightness slider, beat dots, key of D major and 72 bpm lying on the flat half — **Stage.** The chord and what's next stand up. The diagram, the brightness slider, and the key lie flat. It reads like a music stand.

The song chart on a half-folded iPhone Duo: the chord D, next A, and its fingering standing on the top half; the bar-by-bar chart, waveform and play button lying on the flat half — **Song chart.** The chord and its fingering on the standing half. The whole chart, bar by bar, with loop and play on the flat half. Tap any bar to loop it.

The 3D tuner on a half-folded iPhone Duo: the Sakura storm scene and the note E2 standing on the top half; the scene picker's key, the tuner button and tuning settings lying on the flat half — **Tuner.** Any of the thirteen 3D scenes stands up. The scene key, Start, and every tuning setting sit on the flat half, so both hands stay on the guitar.

The song chart on an iPhone Duo opened flat: the current chord Em, its diagram and next chord on the left, the whole bar-by-bar chart on the right, the waveform and play button along the bottom — **Opened flat.** Unfold it all the way and you get the wide two-pane layout: the chord on one side, the whole chart on the other.

Song: We Honor You (feat. Julie Morr) · YHWH Worship

What's in the app

Everything Chartless does, in your pocket: a mic that's always with you, a real guitar in your hands, and a screen you can prop on a stand.

TUNER

A seriously deep guitar tuner.

Here's what deep means. Four modes: a single-note needle, a strum mode that reads all six strings from one strum, a strobe, and 3D — thirteen ways to watch pitch that nobody has shipped before, eight classic and five anime. Equal, sweetened, and just intonation tuned to the key of the last song you charted, so open chords ring pure. Capo-aware, so you tune with it clamped and it targets the fretted pitches. Thirty-plus tunings from standard through DADGAD, baritone, 7-string, 5-string bass, mandolin, banjo, cello, and dobro, plus your own custom tunings. Then the setup tools nobody ships: a guided intonation check (open vs. 12th fret, with a saddle verdict), string freshness that hears when a set has gone dead, a stretch-tuning pass for new strings, a drone to tune by ear, and octave stretch curves for guitar and piano.

WHOLE SONG

Charted with hindsight

The decoder reads the entire song before it commits to a chart: key, a beat grid that never drifts, bar lines, and the chords on every beat. Then the chart plays along, one bar highlighted at a time. No guessing at the edge of the audio. Tap any bar to loop it in the player.

THREE WAYS IN

Mic, browser, or file

Listen charts what your band or your guitar is playing right now. Browser charts a video in the browser straight from the player's audio, lossless, ahead of time. File charts a whole recording before you press play. Share a link from any app and Chartless picks it up.

TIME

4/4, 3/4, 6/8, and the 1

Meter detected from the audio, including compound time. Wrong? Pick it. Downbeat off? Tap the 1 while it plays. Tempo locked on the wrong pulse? Tap along and the decoder re-reads the song around your tap. Tuned on a benchmark of real worship recordings.

ANY TUNING

Diagrams for the tuning you're actually in

Pick your instrument and tuning in Settings and every chord diagram is drawn for it. Standard shapes stay hand-made. Drop D, drop C, and 7-string keep the shapes you know with the retuned strings worked out. Open G and open D get barre shapes. DADGAD gets the drone voicings you'd actually play. Left-handed, too.

CAPO

A capo advisor that knows your tuning

Song in D♭ on a DADGAD guitar? "Capo 6, play G shapes," with the key you'd play in listed next to every fret. Pick it and the names, the diagrams, and the nut label all follow. Recommendations only until you say so.

PRACTICE

A practice room in your pocket

Build a progression or import it from any charted song, set the tempo (or tap it), pick a time signature, and loop it. Voice-led chords played by a synth pad or any of 120 sampled General MIDI instruments, an arpeggiator, a click, and a fingering diagram that follows your instrument.

STAGE

Stage mode with a brightness slider

Chord as big as the phone, the next one underneath, beat dots, key and tempo, and your own brightness control so a dark stage stays dark. Turn the phone sideways and it opens by itself.

CHORD SHEET

Edit, then export a PDF

Every chart becomes a chord sheet you can clean up: remove a mistaken chord, fix a bar, then export a PDF laid out like the extension's. Or send it to the practice room, or look the song up on Ultimate Guitar, SongSelect, or Google.

MIC EXTRAS

Ideas for the next chord

Playing by feel? In mic mode the app offers where to go next from the chord you're on: safe, lift, or shade, with the why behind each. Nashville numbers as an instrument, so the whole chart reads 1 · 4 · 5.

AI CHECK

Is this song AI-generated?

In the browser, one tap reads the page's own labels and a few audio tells and gives you a verdict with the reasons. Uploaded before 2023? That's a hard no, and it says so.

PRIVATE

Still no AI, still no cloud

Classic signal processing on the phone. Audio is never uploaded, never recorded, never used to train anything. Songs you chart stay on your device.

SWEETENED TUNING

Tune once. Hear your guitar ring like it did in the store.

Here's a secret every guitar tech knows and almost no tuner will tell you: a guitar tuned dead-on to the needle is not in tune with itself. The math that lets one guitar play in every key asks every note to give a little. So your open G rings, your open D shimmers a hair, and you reach for the tuner again without knowing why.

Sweetened is one tap. Chartless nudges each string by an amount you'd never hear on its own, and the chords you actually play stop fighting and start singing. Open chords bloom. Barre chords sit still. The wobble you learned to live with is just gone.

Flip on Just and it goes a step further: it tunes to the key of the last song you charted, so the chords in that song ring pure. Change songs, tune again, twelve seconds. The kind of thing you used to need a session player's ear for, now living in your pocket.

It's not magic. It's arithmetic, done for you, and it sounds like magic.

Screenshots

The Chart tab: Listen, Browser, and File as three equal circles, with two recent songs underneath, We Honor You and Surely Suddenly (Waylon's Song) — **Three doors.** Mic, browser, or file. Recent songs remember their key, tempo, and loop.

Bar by bar. The whole song decoded first, then the chord, its diagram, and the bar ribbon ride along as it plays. "We Honor You (feat. Julie Morr)". Live capture.

A whole-song chart of an audio file playing back: 6/8 detected, the waveform timeline, bars lighting up in time — **A file, charted before it plays.** Julie Morr's "Surely Suddenly (Waylon's Song)": 6/8 found on its own, every bar decoded with hindsight.

The same song with Piano as the instrument: a D chord with the keys lit on a one-octave keyboard — **Piano.** Pick an instrument in Settings and every diagram follows. Keys light up for the triad.

The same song on ukulele: a D shape on four strings, tuning badge reading Ukulele, gCEA — **Ukulele.** Nine instruments: guitar, baritone, uke, baritone uke, mandolin, banjo, bass, piano, and Nashville numbers.

Surely Suddenly (Waylon's Song) in A major on a guitar in DADGAD: tuning badge reading DADGAD drone, the advisor recommending capo 2 and G shapes, and an E chord diagram — **Any tuning.** DADGAD with drone voicings, and a capo advisor that knows it: "capo 2, play G shapes." Standard, drop, open, and modal tunings all get their own shapes.

Stage. Readable from the drummer's seat, with your own brightness slider. Live capture.

Strum mode: all six strings read from one strum, each with its own cents offset, four flagged as needing a touch — **Strum all six.** One strum, six readings. It tells you which strings need a touch and leaves the rest alone.

3D tuner, beat helix: a coil of beads spinning while the note is sharp, then collapsing into a straight green rod as it locks on E2 — **3D tuner: the beat helix.** Sharp winds the coil one way, flat the other, faster the further off. In tune, it collapses into a still, straight rod. Amber sharp, blue flat, green locked.

3D tuner, Shepard helix: a spiral of labeled semitones, a dot sliding along it and snapping onto the E rung — **Shepard helix.** Chromatic, any note. Every semitone is a labeled rung on a five-octave spiral; the dot rides to whatever you play and lights the rung when you're there.

3D tuner, cymatics: a cloud of sand grains scattering while the note is off, then settling into a Chladni nodal pattern as it locks — **Cymatics.** Sand on a Chladni plate. Off pitch it smears and the plate tilts; in tune it settles into a crisp figure. Every note rings its own.

3D tuner, Sakura storm: pink petals swirling in a ring while the note reads sharp — **Sakura storm.** One of five anime scenes. Off pitch the wind blows the petals, harder the further off; in tune the wind dies and they gather into a slow ring.

3D tuner, Sumi-e: an ink stroke closed into a circle on cream paper, the note E2 locked in green — **Sumi-e.** A brush stroke on rice paper. It runs ragged and splatters while you're off; in tune it closes into a clean circle.

3D tuner, Mecha HUD: a hexagonal reticle collapsed on target with LOCK across the middle — **Mecha HUD.** A targeting reticle that tracks your pitch and collapses onto the target. Locked, it says so.

3D tuner, glide slope: concentric green rings with the dot dead center, E2 locked at 82.4 Hz — **Glide slope.** Fly the approach. Sharp, you're above the centerline; flat, below. In tune, you go dead center through every ring.

All thirteen 3D tuner scenes in a grid, classic and anime, each labeled — **Thirteen to choose from.** Eight classic: beat helix, gravity bowl, orbit, Shepard helix, cymatics, glide slope, phase sphere, locked strings. Five anime: charge, speed lines, Mecha HUD, Sakura storm, sumi-e. Swipe the picture to change scenes.

The tuning menu: guitar tunings from standard through drop D, E-flat, D standard, drop C, double drop D, C standard, then open and modal tunings — **Thirty-plus tunings.** Standard, dropped, open, modal, baritone, 7-string, bass, uke, mandolin, banjo, cello, dobro. Grouped so you can find yours.

The custom tuning editor: a name field and a grid of notes per string, low to high, spelling out E2 A2 D3 G3 B3 E4 — **Or make your own.** Name it, tap a note per string, save. It shows up in the tuner and in the chord diagrams.

The practice tab: a G-sharp chord looping on Electric Piano 1 at 114 bpm in 4/4 with a guitar diagram — **Practice.** Loop a progression on any of 120 instruments, tap the tempo, watch the diagram change.

On iPad

Same app, more room. The 3D scene, the note, and every tuner setting fit on one screen.

The 3D tuner on iPad, the Mecha HUD scene locked on E2 with LOCK across the reticle, the sidebar and tuner settings around it — **Mecha HUD on iPad.** Locked on E2. The sidebar keeps Chart, Practice, Strings and Songs one tap away.

3D tuner on iPad, cymatics: sand on a plate settled into a crisp nodal figure, E2 locked — **Cymatics on iPad.** Sand on a plate, settled into a clean figure. Every note rings its own.

Chrome extension vs. iPhone app

Since Chrome 2.0 they're the same app: one engine, one privacy stance, the same tuner, chart, practice room and strings. They differ in where they live and what they can reach. Both are free to start, with Chartless Pro as a subscription, because they keep growing.

	Chrome extension	iPhone app
Where it lives	Chrome's side panel, next to the page you're playing, or a full tab	Your phone, on a music stand or in your pocket
What it can hear	Any browser tab, your mic, or an audio file on your computer	Your mic, a web player inside the app, or any audio file on the phone
When it charts	Live as the song plays, re-read into a whole-song chart as it goes; files charted whole first	The whole song first, then plays it back with the chart already drawn (mic stays live)
Bars and meter	Bar-by-bar chart, 4/4 · 3/4 · 6/8 detected, Tap the 1, tap tempo, loop any bars	Bar-by-bar chart, 4/4 · 3/4 · 6/8 detected, Tap the 1, tap-tempo hint, loop any bars
Chord diagrams	Nine instruments, thirty-plus tunings, left-handed	Nine instruments, thirty-plus tunings, drone and barre styles, left-handed
Capo advisor	Knows your tuning	Knows your tuning; shows the key you'd play in at every fret
Tuner	The full suite: strum, strobe, thirteen 3D scenes, temperaments, capo-aware, custom tunings, intonation check, string freshness, stretch, drone	The full suite: strum, strobe, thirteen 3D scenes, temperaments, capo-aware, custom tunings, intonation check, string freshness, stretch, drone
Practice room	Loop any progression on 120+ sampled instruments, arpeggiator, click	Loop any progression on 120+ sampled instruments, arpeggiator, click
Strings	Fingerprint a fresh set, check how far it's drifted	Fingerprint a fresh set, check how far it's drifted
Export	Editable chord sheet, PDF, copy as text, send to practice	Editable chord sheet, PDF, share as text, send to practice
Stage view	Full-screen chord, pop it out into its own window	Full-screen chord, auto in landscape, brightness slider
Price	Free, Pro $39.99/yr or $9.99/mo (7-day free trial)	Subscription, try it free first. Details at launch.

The whole song, charted before it plays.

See it in action