OpenString

Buy it once. It is yours.

Guitar tools
you own.

Tuner, metronome, chord shapes and your own songbook - every tool included, with no subscription and no account. Your songs live on your phone, not on someone else’s server.

Download on the App Store

On the App Store for iPhone.

OpenString’s standard guitar tuner with six string selectors and a flat-to-sharp pitch guide
The OpenString iPhone app

Works offline

No account needed

Your songs stay on your device

Not a rented
song catalog.

Most guitar apps sell you a monthly pass to a library of other people’s songs, then split the tools across a free and a paid tier. OpenString is the other shape.

A subscription catalog

  • Pay every month, forever
  • Tools split across free and paid tiers
  • Needs an account and a connection
  • Your charts live on their server

OpenString

  • One purchase
  • Every tool included
  • Works offline, no account
  • Your charts stay on your phone, exportable

From the first string
to the last chorus.

Tune up, set your pace and keep the music you’re working on close at hand.

Learn

Hear which string
needs your finger.

Eight short lessons take you from your first Em to your first song. OpenString listens while you strum and marks each string: it rang, it was muted, or it did not come through clearly. So you know which finger to move, not just that something sounded off.

Listening happens on your phone, so lessons work offline too.

Em, G, C and D · Chord changes · Strumming in time · Your first song

An OpenString lesson on the Em chord, marking which strings rang after a strum

Guitar tuner

Start in tune.

Choose a string, pluck it and follow the pitch guide. Standard six-string tuning keeps the essentials easy to find, from low E to high E.

Microphone tuning · Clear flat and sharp guidance

E2A2D3G3B3E4

Metronome

Find your rhythm.

Slow a tricky passage down or build up the pace. Set a tempo from 40–240 BPM, or tap the beat you have in mind.

Tap tempo · 4/4 time · First-beat accent

OpenString metronome with tempo adjustments, four beat indicators and tap tempo

Chord library

Find your next chord.

Look up common major, minor and seventh chords without leaving your practice. Clear diagrams show where your fingers go in standard guitar tuning.

Chord fingerings · Open and muted string labels

OpenString chord library showing guitar chord diagrams and finger positions

Personal songbook

Your words.
Your chords. Your key.

Keep your own lyrics and chords together. Transpose the displayed chords and save capo preferences while your original song stays intact.

Create and edit songs on your phone, then export your library and restore it when you need it.

Local saving · Transpose and capo · Backup and restore

Bring the songs you love to play.

Your songbook starts with you. Add your own lyrics and chord charts; no commercial song catalog is included.

How song backups work

Made for time with your guitar.

Practice offline, without an account. Microphone audio is processed on your device, and your songbook stays local unless you choose to export it.

Read about your privacy

OpenString is available on the App Store. Get it on the App Store