Intonia 4+

This app is exactly what I was looking for. It’s very simple and has no unnecessary features or ads, which says a lot about the developers. Changing keys is easy and it reads audio almost instantaneously. It also shows note duration so you can visually see whether your rhythm is even and consistent.

It is worth mentioning that, at least from my experience, it works best for stringed instruments, specifically bowed string instruments. It’ll only pick up specs of a piano or guitar, for example, but that’s fine since those instruments don’t have to worry about intonation. It may work for brass and woodwind instruments but I can’t say. The fact that it only solidly registers my violin has actually come in handy since any background noise is not an issue.

This app not only showed me why my playing didn’t sound so great, but also how terribly uneven my vibrato was. After using this for about six months, my playing is much more in tune, and my vibrato is coming along.

As a calligraphic artist, I especially enjoy the way the internation line looks like a brush stroke. When it’s in tune and the vibrato is steady, it’s a work of art. When it’s out of tune and you have a lot of bow noise and your finger isn’t quite contacting the fingerboard, it looks as terrible as it sounds!

Love it. It is truly an inspired app.

I used the Mac desktop version of intonia years ago to work on my intonation (on fiddle). I just got the newly released iPhone version, which is even better than I remember the desktop version being because it allows you to import music files (even from cloud servers, like Google Drive). This is a fantastic feature for transcribing recordings because you can see all the note pitches in real time as the music plays.