Found under: Settings > Display > Scaling

When displaying songs on your device, you will be unlikely to have font as large as can be printed on an A4 sheet of paper, unless your device screen is this big!  To maximise the size of the text, OpenSongApp has a scaling feature that tries to do this automatically.

One important thing to remember is that lyrics are NOT wrapped over multiple lines.  If you write lyrics with very long lines, the app will try to show these long lines to the screen on a single line.  When creating OpenSong song files, you may have to experiment until you know how many words/characters you can try to squeeze onto a single line.

Once your song file is ready, the app will give you three autoscale options:

Depending on which option you choose, you can specify further options:

Scaling off (not recommended)

Note that text may be wider and taller than the screen height, or not fully use the available space.

The text is wider than the screen and would need scrolled to the right as well as down to see everything
The song needs to be scrolled down, but there is lots of wasted space to the right.
The font could be almost twice the size in landscape mode

Scaling width only (recommended for smaller screens).  This is the default setting

The text will be scaled so that the longest line fits the full width of the screen.  You will likely have to scroll down to see the full song.

The text is scaled so the maximum width of the screen is used.  Scrolling down is required
The text needs to be scrolled down.  The space to the right is due to longer lines lower down
After scrolling down, the longest line completely fills the screen width

Scaling width and height.  Recommended for larger screens

The text will be scaled so that the the text is as large as can be whilst showing the entire song on the screen.  Sometimes this will show as multiple columns (which can be set to scale independently of each other).  This means no scrolling is required.  Note that columns are worked out automatically to be the best split of songs to allow maximum scaling.

The text is scaled so the entire song is visible.  No scrolling required.
Independent column scaling on.  Each column is scaled to the maximum text size while still fitting the column width and height.
Independent column scaling off.  Both columns have the same text size.

You can also set a Page button or a Custom gesture to toggle autoscale to width only or full scale.