Every THRASS phoneme plus every keyword grapheme. Tap the orange slot on the left of each row to record the pure sound (e.g. "huh"). Tap any keyword chip to record that whole word (e.g. "hand"). Green = done.
Inside the recorder you can swipe through with the arrows to bang through them quickly. Long-press a green slot to delete a recording.
The Spelling List section pulls from the admin page — every word you've added shows up here. If a spelling word matches a THRASS keyword (e.g. "jam") it shares one recording across both slots.