Controls on mobile apps - am I missing something?

[Ben Rubinstein]

My previous mobile app dabbling had involved entirely custom interfaces. Now 
I'm trying to create a more straightforward app with a more conventional 
interface - and I'm getting a horrible dichotomy between the widgets (header 
bar, navigation bar, switch control, segmented control) and the traditional 
controls (radio buttons, sliders, progress bars, etc).  The latter look fine 
on Mac; but on iOS, they've gone back to Motif, which is to say several decades.

I found the "theme" property introduced in 8.0 and thought that perhaps this 
is what I'd been missing. But I added some temporary controls in my app to 
toggle the theme of this stack ... and it didn't seem to make any difference. 
(Or rather, there was a visible difference - the text size and possibly font 
of some elements where I'd left them at the default changed; but the radio 
buttons, sliders etc were still horrible.)

Am I missing something: or is there really nothing better than the Motif 
rendering for these basic controls?

TIA,

Ben