Stackapella and Howli
As of November 2026
Both help you learn harmony parts with live pitch feedback, and record them. Howli is an iPhone and Android app with a lifetime price and 45 languages. Stackapella runs in your browser, with free courses and harmony suggested for your own tunes.
Who each is for
Howli is for
- Singers who want an app on iPhone or Android.
- Anyone who'd rather buy once: it has a lifetime price.
- Bringing in your own arrangement as MusicXML or MIDI.
Stackapella is for
- Starting from your very first note, with free courses up to four-part harmony.
- Getting alto, tenor and bass suggested for a tune you sing.
- Singing in a browser on any phone or computer, and practising with a choir.
Side by side
| Howli | Stackapella | |
|---|---|---|
| Where it runs | iPhone and Android apps, and a free song editor on the web123 | In any modern browser, on phones and computers. It installs like an app; there's no app-store app yet |
| Price | Free, with a daily recording limit on its built-in songs. Unlimited: $3.99 a month, $14.99 a year, or $24.99 once (US App Store)1 | Free to learn. Plus is $4.99 a month or $39.99 a year |
| Learn a part by ear, with live pitch feedback | Yes: hear each part, then sing it with live pitch feedback12 | Yes: hear each part from a guide voice, then sing it while your notes light up as you hit them |
| Record your own parts, stacked in time | Yes: record each part, or two to six layers in Freestyle1 | Yes: record each part over the ones before, lined up in time |
| Harmony parts suggested for your own tune | Not stated: parts come from its built-in songs, or you write or import them1 | Yes: sing or hum a tune, and alto, tenor and bass are suggested to fit it |
| A course from first note to harmony | Not stated | Yes: free courses, from your first note to four-part harmony, and on skills and styles |
| Choir tools | Not stated. Duets with a friend, and song codes to share an arrangement12 | Choir groups and practice tracks |
| Bring in sheet music (MusicXML or MIDI) | Yes: MusicXML and MIDI, in its web editor1 | Not yet: sing or hum a tune, write it in the note editor, or open a Stackapella file |
| Languages | 451 | English |
| Open source | Not stated | Yes, under the Attribution Assurance License |
"Not stated" means we couldn't find it in the product's own listing or website, not that it's missing.
Where each fits better
Where Howli fits better
- You want an app from the App Store or Google Play.
- You'd like to pay once, or sing in one of its 45 languages.
- You already have an arrangement as MusicXML or MIDI.
Where Stackapella fits better
- You're new to singing and want a course that starts at the first note.
- You want harmony parts suggested for a tune of your own.
- You sing with a choir and want its groups and practice tracks.
Questions
Does Stackapella work on Android?
Yes, in the browser on Android phones, and it installs like an app. There's no app-store app yet.
Can I bring MusicXML or MIDI into Stackapella?
Not yet. You can sing or write a tune in the note editor, or open a Stackapella file.
Is Stackapella free?
Yes: every course and every song in the library, with a free account, and unlimited workouts, your history, singing with friends and choir groups. Plus, for $4.99 a month or $39.99 a year, adds more storage, MP3 and stems, and unlimited private arrangements.
Try Stackapella
Start with your comfortable note. No account needed, and every course is free.
Sources
Seen 2 November 2026, on each product's own listing or website.
Product names belong to their owners. Stackapella isn't connected with any of these products or their makers.