Both. Fretscape works in portrait and landscape on phones and tablets, whether you're using the Android app or the web. Most screens look broadly the same in either orientation — the chord search, voicing list, favourites, and settings just stretch or shrink to fit. A couple of features do reshape themselves for landscape, though, and they're easier to use that way.

Features that change layout when you rotate

Reverse Chord Lookup. Whichever way you hold the phone, the matched chords appear below the fretboard. Landscape is still the better choice on a phone — the fretboard gets the full horizontal width of your screen, which makes tapping notes a lot less fiddly.

The Progression Builder. In portrait, the chord row and the editing panel share the screen and feel cramped on smaller phones. In landscape, you get a wider strip of chords and proper room for the controls. If you find yourself doing serious progression work on a phone, rotate to landscape — see The progression builder doesn't fit on my phone screen for the longer answer.

Everything else (chord search, voicings, the chord builder, favourites, settings) keeps the same layout in both orientations — it just resizes.

How to lock orientation

If your phone keeps flipping the layout when you don't want it to, lock the rotation from your phone's quick settings panel (the swipe-down menu) — not from inside Fretscape. Fretscape doesn't have its own rotation lock; it follows whatever your phone is set to.

On Android, look for Auto-rotate or a small portrait/landscape icon in quick settings. Tap it off to lock the current orientation.

What about tablets?

iPads and Android tablets handle both orientations comfortably, and most users naturally hold them in landscape. The Progression Builder in particular feels much more like the desktop version on a tablet in landscape — closer to the experience the web app gives you on a laptop.