Comment by reaperducer

But will you gain anything by building for it?

Nothing ventured, nothing gained.

Will you see noticeably more users or people choosing another alternative because you didn't specifically building the app for Duo?

I haven't done iOS development in a long time, but my understanding is that if your iPhone app is designed well and uses all of Apple's recommended methods, adjusting for different screen sizes and orientations is fairly easy.

If you decided to go cheap/easy/dumb from the outset, then you made your bed, and now you get to lie in it.