left hand first.
most phone keyboards assume the whole width of the screen is easy to reach. when you hold your iphone in your left hand, the far right keys can be the awkward part.
a left-positioned keyboard makes the active typing area shorter without asking you to change your grip.
apple and una mano.
iphone has a built-in left-handed layout. touch and hold the emoji or globe key, then choose the left layout.
una mano is useful when you want a left position that is quick to return to, with the keyboard controls gathered to your chosen side.
switch sides when life does.
you might type with your left hand on the train and your right hand while holding a bag. una mano lets you move from left to centre to right without changing the keyboard layout you know.