How to split and layer

Does anyone know if its possible to split or layer 2 different sounds on this app.

It’s possible by using 2 keyboard rows that play 2 different tracks (instruments), see
https://www.xewton.com/musicstudio/doc/?id=6#Keyboard_row_selector and
https://www.xewton.com/musicstudio/doc/?id=5#Keyboard_layout_button

On iOS, using external hardware or apps as MIDI input, you can even set a split point here:
https://www.xewton.com/musicstudio/doc/?id=10#Keyboard_split_point