An iPad port could definitely work, control-wise. iPhone.. I don't see it happening, the screen is too small and you need accuracy.
Kind of a shame, I have no iPad

Controls as I see them:
Drag from Naija to swim
Hold on Naija to activate the singing when in normal form. Otherwise does nothing
Tap anywhere other than Naija to shoot (could also work while swimming this way)
Tap anywhere other than Naija using two fingers to thrust. Can also keep swimming after this, even if one of the fingers is released
The map part of the screen is still there, including the pause menu. Tap the pause button to access the menu, double-tap the map to access world map.
Tap on Naija with two fingers to go back to normal form
Controls in the world map should be obvious. Drag to pan, tap to select, etc.
Did I miss anything?
Sure, you can't play using only one hand like you could on a PC, but it's still good!
I really hope this is done. Obviously there would have to be optimizations but it would be worth it
